Europe’s largest Consuming single pylon stay cable bridge ... · Stay Cables 57 COVER FEATURE: Europe’s largest single pylon stay cable bridge The dramatic new Sava Bridge has

Consuming passion for LNGExpertize in cryogenic containment

meets market demand

www.bbrnetwork.com Sixth Edition 2012

The Christchurchearthquakes – the BBR Network’sresponseImproved damage-resistantconstruction techniques

Europe’s largestsingle pylon stay cable bridgeTimely achievement of unique design for new Sava Bridge

THE MAGAZINE OF THE GLOBAL BBR NETWORK OF EXPERTS

First of its kindin the worldFranchised network setsnew benchmarks

ElectrifyingperformanceStrength and flexibility

to drive energysector projects

BBR VT International Ltd is the Technical Headquarters and Business Development Centre ofthe BBR Network located in Switzerland. The shareholders of BBR VT International Ltd are:BBR Holding Ltd (Switzerland), a subsidiary of the Tectus Group (Switzerland); SpennteknikkInternational AS (Norway), a member of the KB Group (Norway); BBR Pretensados y Te�cnicasEspeciales PTE, S.L. (Spain), a member of the FCC Group (Spain).

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The BBR Network is recognized as the leading group of specializedengineering contractors in the field of post-tensioning, stay cable and relatedconstruction engineering. The innovation and technical excellence, broughttogether in 1944 by its three Swiss founders – Antonio Brandestini, MaxBirkenmaier and Mirko Robin Ros – continues, almost 70 years later, in thatsame ethos and enterprising style.From technical headquarters in Switzerland, the BBR Network reaches outaround the globe and has at its disposal some of the most talented engineersand technicians, as well as the very latest internationally approved technology.

THE GLOBAL BBR NETWORKWithin the Global BBR Network, established traditions and strong local rootsare combined with the latest thinking and leading edge technology. BBR grantseach local BBR Network member access to the latest technical knowledge andresources – and facilitates the exchange of information on a broad scale andwithin international partnering alliances. Such global alliances and co-operationscreate local competitive advantages in dealing with, for example, efficienttendering, availability of specialists and specialized equipment or transfer oftechnical know-how.

ACTIVITIES OF THE NETWORKAll BBR Network members are well-respected within their local businesscommunities and have built strong connections in their respective regions.They are all structured differently to suit the local market and offer a varietyof construction services, in addition to the traditional core business of post-tensioning.

BBR TECHNOLOGIESBBR technologies have been applied to a vast array of different structures – such as bridges, buildings, cryogenic LNG tanks, dams, marine structures,nuclear power stations, retaining walls, tanks, silos, towers, tunnels, wastewatertreatment plants, water reservoirs and wind farms. The BBR brands andtrademarks – CONA, BBRV, HiAm, DINA, SWIF, BBR E-Trace and CONNAECT– are recognized worldwide.The BBR Network has a track record of excellence and innovative approaches– with thousands of structures built using BBR technologies. While BBR’shistory goes back over 65 years, the BBR Network is focused on constructingthe future – with professionalism, innovation and the very latest technology.

After reading the many articles and features in thisedition of CONNAECT, you will be in no doubt thatthe BBR Network has ‘come of age’. This unique

franchise concept has brought BBR Network Memberscloser together and promoted many improvements, both intechnology and the way in which it is deployed. Thisbecomes particularly evident when you consider the overallgreen credentials of BBR technology, the scale of suchprojects as the elegant Sava Bridge in Belgrade, ourconsistently high achievement in the fields of LNGcontainment – and services to the energy sector in general.

The flexibility of BBR technology, combined with theexpertize of the BBR Network, is realizing somecommercially and technically compelling solutions. In theinfrastructure sector, we are supporting the creation ofpractical yet exciting structures and, for buildings, we arehelping to maximise usage of space – and budgets.

Our expertize across all sectors has been ably demonstratedby teams around the world – the application of BBRtechnology is as diverse as the people who apply it. The oneconstant throughout the BBR Network is the blend ofengineering skills, ingenuity and innovation which is focusedon each and every challenge. We look forward to supportingthese endeavors over the coming year and being able tocelebrate still further achievements in the next edition ofCONNAECT magazine.

1CONNÆCT

Consuming passion for LNG

Expertize in cryogenic containment meets market demand

www.bbrnetwork.com Sixth Edition 2012

The Christchurchearthquakes – the BBR Network’sresponseImproved damage-resistantconstruction techniques

Europe’s largestsingle pylon stay cable bridgeTimely achievement of unique design for new Sava Bridge

THE MAGAZINE OF THE GLOBAL BBR NETWORK OF EXPERTS

First of its kindin the worldFranchised network setsnew benchmarks

ElectrifyingperformanceStrength and flexibility

to drive energysector projects

Marcel PoserChairmanBBR VT International Ltd

Thomas RichliHead of Business DevelopmentBBR VT International Ltd

EDITORIAL OFFICE BBR VT International LtdTechnical Headquarters and Business Development CentreSwitzerlandwww.bbrnetwork.com [email protected]

EDITOR Jane SandyCONTRIBUTING EDITORThomas RichliDESIGNER Caroline DonnerADMINISTRATIVE ASSISTANTS Beth Skirrow, Cecile Kopp

CONTRIBUTORSDeirdre Allen, Enrique Arana, Tie King Bang, Kresimir Bogadi, NorbertBogensperger, Karol Bucholc, Antonio Caballero, Yeo Swee Choo, Yan ManChung, Sam Fassaie, Richard Gaskill, Ben Grundlehner, Karolina Haponik, MarcinHarhala, Peter Higgins, Warwick Ironmonger, Hugo Jackson, Mika Jakau, MarkKurtovich, David Olivares Latorre, Michael Losinski, Piedad Lucas, BartoszLukijaniuk, George Marinos, Kew Kim Mei, Claude Neant, Damir Pavicic, TerryPalmer, Jose Luis Plaza, Mark Seisun, Keith Snow, Jacek Sowa, Lim Suan Suan,Pawel Surman, Paul Wymer, Marcin Wyrczynski, Mohd Yusri, Roland Zachar

PUBLISHER BBR VT International Ltd NUMBER OF COPIES 10,000Printed in EnglandEvery effort is made to ensure that the content of this edition is accurate butthe publisher accepts no responsibility for effects arising there from.p-ISSN 1664-6606e-ISSN 1664-6614© BBR VT International Ltd 2012

SOURCES AND REFERENCESBridges section Poland’s longest bridge: http://en.wikipedia.org Buildings section Grand result & International showcase:http://en.wikipedia.orgTanks & Silos section Consuming passion for LNG:www.reportsnreports.com, www.streamrgn.com & Hydrocarbon Asia, atwww.safan.comExpertise & easy handling: www.agrana.com & http://en.wikipedia.orgStay Cables section Europe’s longest stay cable bridge: www.savabridge.comLandmark Structures section Harnessing hydro:www.engineersaustralia.org.au & www.hydro.com.auChasing the wind: Global Wind Report, Annual Market Update 2010, GlobalWind Energy Council, at www.gwec.net & Wind in Power, 2010 EuropeanStatistics, February 2011, at www.ewea.org

Editorial, sources and references

2 CONNÆCT

Talking BBR

4 Innovatively speaking

6 COVER FEATURE:First of its kind in the worldThe BBR Network franchise is thefirst of its kind in the world. It wasformed to harness the spirit ofinternational networking andcooperation to deliver excellence inconstruction and the very highestlevel of customer service.

8 News from BBR R&D and Engineering

10 Coming home

Bridges

11 Altiani Bridge, Corsica, France

14 Malaga Airport South Approach,Andalucia, Spain

15 Entertainment City Bridges, Lusail,Qatar

16 Infrastructure projects, Poland

18 Waipuna Bridge, Auckland, NewZealand

19 Belconnen Way Overbridge, Canberra,Australia

22 A1 Motorway Bridge, Grudziadz,Poland

23 Seitenhafenbrücke, Vienna, Austria

24 Pisuerga River Bridge, Valladolid, Spain

26 Sungai Teru Crossing, Miri, Sarawak,Malaysia

27 Odra Viaduct, Zagreb, Croatia

27 Traunbrücke, A1 Motorway,Steyrermühl, Austria

28 MAIN FEATURE:Spanning urban green

Featuring a spectacular whiteconcrete bowstring arch, the new LasLlamas Bridge, across a city centrepark, provides a much neededconnection between two key areas ofSantander, Spain.

30 R1 Motorway Bridge, Nitra, Slovenia

31 Ribnica Bridge, Podgorica, Montenegro

31 A1 Motorway, Upper Silesia, Poland

Buildings

32 Royal North Shore HospitalRedevelopment, Sydney, Australia

34 Opera house rehearsal stage, Vienna,Austria

35 Arena Center, Zagreb, Croatia

36 Parking structures, Malaysia, Poland andNew Zealand

37 K-Mart distribution warehouse,Auckland, New Zealand

38 Dee Why Grand, Sydney, Australia

39 Essex Magistrates’ Courts, Essex, UK

40 ADNOC Headquarters, Abu Dhabi,United Arab Emirates

41 School of the Arts, Singapore

42 Office buildings, Warsaw & Szczecin,Poland

43 Asia Square, Marina Bay, Singapore

43 Plaza 33, Petaling Jaya, Malaysia

44 ExCeL Exhibition Centre, London, UK

45 BIW Hotel, Bahrain, United ArabEmirates

46 University buildings, UK & Australia

48 Railway Viaduct, Wroclaw, Poland

Tanks & Silos

50 Consuming passion for LNG

52 LNG tanks, Gijon, Spain

54 Sugar silo, Tulln, Austria

56 4th NGL Train project, Abu Dhabi,United Arab Emirates

Contents

2nd Coentunnel,Amsterdam, NetherlandsImmersed tube tunnelconstruction has becomesomething of a tradition inthe Netherlands, this featurearticle outlines the roleplayed by BBR.

Royal North Shore Hospital Redevelopment, Sydney, AustraliaThe benefits of post-tensioning were harnessed to provide an economicallyviable, strong and flexible solution for the new facilities which included a helipad.

Strong and healthy

MAIN FEATURE: Sinking with success

3CONNÆCT

Stay Cables

57 COVER FEATURE:Europe’s largest single pylon staycable bridge

The dramatic new Sava Bridge hasbecome a major landmark for the cityof Belgrade, Serbia. BBR Stay Cabletechnology was effectively andefficiently installed to meet a greatlyshortened program. Reflections on itsconstruction and stay cable bridgeengineering design are provided byDipl.-Ing. Holger Svensson ofLeonhardt Andrä & Partner.

62 River Minho Bridge, Lugo, Spain

63 Stay cable footbridge, Witrylow, Poland

64 Basarab Flyover Bypass, Bucharest,Romania

67 Pedestrian bridge, Blackburn, SouthAfrica

68 Otopeni Bridge, Bucharest, Romania

Special Applications

69 2nd Coentunnel, Amsterdam,Netherlands

72 Sungai Siol Bridge, Matang, Sarawak,Malaysia

72 River Danube Bridge, Vidin-Calafat,Bulgaria & Romania

74 Wellington Dam, Collie, WesternAustralia

76 Reinforced soil structures, Poland

77 Prill Tower, Moranbah, Queensland,Australia

78 Al-Wehdah Dam, Irbid, Jordan

78 Triathlon VIP Zone, London, UK

MRR

79 The Christchurch earthquakes – theBBR Network’s response

85 Semedela Overpass, Koper, Slovenia

86 Queens Wharf, Auckland, NewZealand

Landmark Structures87 COVER FEATURE:

Eletrifying performanceFrom the massive heavy engineeringfeats for hydroelectric damstrengthening to the high-tech, highsafety environment of nuclearinstallations and onto the elegance ofwind towers, BBR technology showsthat it has the strength and flexibilityto meet the very different challengesset by today’s energy sector.

94 BBR Worldwide Directory

Altiani Bridge, Corsica, FranceRealization of this dramatic new structure, designedto reflect the adjacent medieval bridge, demandedinnovation and precision engineering.

11As world LNG tradecontinues to increase, wereview the market andaward-winning approach ofthe BBR Network indelivering the specializedcontainment facilitiesrequired by this sector.

We look at how earlier BBR projects fared in the cityof Christchurch and offer insights on lessons learntand new seismic technologies.

Historic landmark

COVER FEATURE: Consuming passionfor LNG COVER FEATURE:

The Christchurch earthquakes

4 CONNÆCT

WHY CHOOSE INNOVATION AS ATHEME?Simply because absolutely everything we dois about innovation. This first became clear tome while making visits to franchisees andconstruction sites – and indeed ourfranchisees’ customers – around the world.Each construction project is unique – there’sno such thing as a standard product in termsof a structure. It has to be that way to meetthe specific needs of customers and end-users. Actually, we are innovating every timewe start a new project – by using differentengineering techniques and technologycombinations. In fact, when you look throughCONNAECT, you’ll see examples ofengineering innovation everywhere – bothnow and in our past.Then I thought a bit more about the BBRNetwork as a whole – we describe it as anew kind of franchise. Well, in terms of abusiness model, that’s actually innovation too– usually, the franchise concept is applied tothe consumer goods market rather than tosophisticated construction engineering andservices businesses. OK, I guess being Swiss helps us to embraceinnovation as well – it’s somehow in ournational psyche to continuously seekimprovement. This is especially good newswhen you also consider that the media arereporting that, due to the strength of theSwiss Franc, it’s now imperative that Swiss-based companies should innovate evenmore. According to the Global InnovationIndex, Switzerland is already at the top of theinnovation league table. So, lots of creativityand lateral thinking is going on here!

HOW DO YOU DEFINE‘INNOVATION’?In simple terms, it’s the ability to takesomething we already have or do and make

it better, so that it’s more suitable for theway we live and work. If you look intohistory, you’ll see that the human race hasprogressively improved all sorts of productsand processes over the years. The BBR storyis actually a good reflection of this –progressive improvement of our technologyand ‘go-to-market’ strategy has ensured notonly our continuous success, but also thatthe construction industry has access to thevery latest technology and engineering.Take prestressing, for example. It’s beenaround for more than a century, havingevolved from the shipbuilding industry – butit’s how you improve it that counts. That’swhat we do – improve and renew.

… BUT ISN’T THIS JUST ‘RE-INVENTING THE WHEEL’?Exactly, that’s my whole point! Innovationshouldn’t be confused with invention –innovation isn’t about inventing anything new,rather just improving what already exists.When there’s already an established demandfor the product or service, with marketfeedback and expert observation, it is oftendesirable or necessary to enhance theoffering or approach. At BBR, we’ve beenlistening to customer feedback for years andour latest response has been to develop anew range of improved technology. And wewill never stop listening to what the markettells us, it’s our reason for existing.

InnovativelyspeakingSince its foundation almost 70 years ago,

innovation has been at the very heart of BBR and continues to provide the driving

force for technological and commercial advances.Thomas Richli, Head of Business Development ofBBR VT International Ltd, explores the nature ofinnovation and its role within today’s market place.

5CONNÆCT

TALKING BBRWHERE DO IDEAS COME FROM

TODAY?There are so many drivers for innovation –the list is almost endless. I guess the mostimportant impetus, in our industry comesfrom an end-user perspective. Ourcustomers have specific needs or wishes andthese drive innovation – they’re a key source.With post-tensioning, you can make so manyamazing structures – large column-freespaces in buildings and long spans for bridges– all that’s needed is our expertise andimagination in applying it.For us from the BBR HQ, other catalystsinclude feedback from our franchisees – withsome 2,000 enquiries a year, we need tomake sure we take on board the lessonslearnt from these and do things a bitdifferently to align ourselves better with whatthe market wants. We also work closely withuniversities and these dialogues are alwaysfood for thought – and often inspire futureimprovements. Industry conferences and ouractive role in technical commissionsfrequently generate issues for us to follow upon too. Of course, we’re always watching ourcompetitors as well – we look at what theydo and strive to improve upon theirapproach. What’s happening in otherindustries influences our business too.There’s input from almost everywhere youlook!Then you have government policies, like theneed for a European Technical Approval(ETA), as well as requirements of industryassociations such as fib and PTI. Right now,it’s pretty clear that the innovationbarometer has moved towards protectingour macro-environment – the planet.Governments around the world areencouraging sustainable practices both bylegislation and by initiating importantdialogues – essentially creating a frameworkfor innovation in green technology andpractices. While BBR technology and techniques have,by their very nature, always promoted asustainable approach, we continue to seekfurther opportunities to refine and enhancetheir green credentials.

HOW DO YOU REMAINCOMPETITIVE?You know, if you look at the requirements ofa franchising system, as a franchisor you areobliged to be innovative – it is stronglyrecommended that you listen to yourfranchisees. You cannot develop a system,product or strategy – and then not touch itfor ten years. This forces us to continuouslyimprove our service and products.

End-user benefits are that they get the latestproven technology, delivered through alocally customised service. Usually, you have atool or a product and give someone thelicence to use it. With the BBR franchise,there is more – franchisees benefit fromlatest approved technology, know-how,strong brands, quality and procurementmanagement and regular training sessions aswell.The BBR franchising model clearly works –there’s been a significant annual growth overthe last couple of years. Even last year, we seta new record for growth.

GIVE US SOME EXAMPLES OF BBRINNOVATION?Recently there have been two excellentexamples of BBR innovation – BBR E-Traceand the BBR HiEx CONA Saddle. These aretypical of the type of innovation we’vedeveloped and rolled out successfully.Originally, BBR E-Trace grew out of arequirement, under ETA, for FactoryProduction Control – which would haveprompted a massive increase in paperwork.So we thought about developing a platformto do this – while also fulfilling procurement

needs and creating an interface forexchanging information, beyond just ordering products and documenting quality.Some years ago, franchisees were beingasked to provide an extradosed system. It was natural that we should look at whatwe could do to offer a saddle solution. We already had a European Approvedsystem, so were able to use part of this and also the HiAm CONA system. Withproven technology for the stays and pylon, all we had to do was to connect these two technologies – and test oursolution to ensure the two technologiesworked together.

WHAT CAN WE EXPECT FROM BBR IN THE FUTURE?Ah … now that would be telling! As youwould expect, our program of testingimproved technology continues and we willbe making announcements about this later.Meanwhile, we are continuing to review allthe requirements and ideas we get from sitevisits, training courses and conferences. Anidea isn’t something you can immediately useto create competitive advantage or improveyour business model. So, having gathered theinformation, we explore what we can do toturn it into a product or a service ultimatelybenefiting end-users and customers.Over coming months, we will be looking atour franchising system and improving ourrole, both as a Network and as a franchisor.Our goal is to continue to grow, so you canbe certain of reading about future innovationin subsequent editions of CONNAECT. l

6 CONNÆCT

GLOBAL BBR NETWORK FRANCHISE

First of its kindin the world

The BBR Network franchise –the largest and first of itskind in the world – evolved

from the licensed business whichhad traded successfully on theinternational scene since the1940s, and has grown in recentyears both in terms ofgeographical coverage andbusiness volume – and is now trulygreater than the sum of its parts.

Bureau BBR, as the company was firstknown, was born of wartime materialshortages – and engineering innovation at itsvery best. The three founders – MaxBirkenmaier, Antonio Brandestini and MirkoRobin Ros – explored the savings to bemade by using pretensioned reinforcementfor concrete support girders.From there, they ventured further – into thedevelopment of a complete range ofprestressing and post-tensioning systems,ground anchors and stay cable anchorages,covering all structural engineeringapplications.

BUILDING THE TEAMOver the years, the successful developmentof BBR continued, with many landmarkprojects featuring in our portfolio, however,this was not enough – our vision was fargreater than this.We wanted to create even closer ties withthe companies and people who were usingBBR technology in their local markets. It wasimportant that this was achieved in a waythat the wealth of expertise could be sharedwith people in other parts of the world and,in turn, be fed back to the Swiss HQ andfuel subsequent improvements in bothtechnology and service.By creating a franchised group – the GlobalBBR Network of Experts – we were able toformalize relationships between the BBR

What is a franchise?The McDonalds fast food business is widely regarded as being one of the world’s earliestand most successful franchise. The BBR Network franchise is broadly similar, with severalkey differences, which make it one of a kind.

FRANCHISE – created when a ‘franchisor’ allows use of his brand or trademarks, know-how and processes, by a ‘franchisee’. Thus franchisees can use a proven concept tofurther develop their own businesses and the franchisor can extend the geographic andmarket reach of his business. In the BBR Network franchise, much more than brands andtrademarks are included – for example, access to approved technology, latest systemapplications, certification, training and marketing communications support.

FRANCHISE AGREEMENT – provides the franchisee with the terms under which heis permitted to operate the business. The BBR franchise agreement includes both thefranchisor’s and franchisee’s obligations using the franchised system applications for afixed period of time, and allows for renewal.

FRANCHISOR – typical responsibilities include system development, continuing productsupport, marketing campaigns and supply chain management. He will want to monitorfranchisee performance. BBR VT International as the franchisor commits to continuouslyimprove the technology, QA, supply chain and know-how transfer.

FRANCHISEE – will agree to follow the rules set out by the franchise agreement andto take an active role in furthering the franchised technology and business aims.Normally, franchisees will pay a start-up fee, followed by annual ‘management servicefees’ or royalties. A BBR franchisee is fully qualified to source, assembly and install thesystem applications to the highest service and quality standards.

7CONNÆCT

head office team and a loyal band ofinternational construction engineeringspecialist companies. The structure andcommitment flowing from this process hasbenefitted – and will continue to benefit –not just the BBR family, but also theconstruction industry as a whole.

GROWING STRENGTHOver recent years, we have focused heavilyon developing new technology, strengtheningof the Network, and creating of a range ofmarketing communications material. Indeed,we have invested many millions of SwissFrancs to produce the most up-to-date andapproved systems.The BBR Network also draws strength fromthe continuously growing sense of ‘family’ feltamong Members. They like attendingconferences and training sessions because ofthe potential for exchanging information withBBR HQ and other franchisees.Training seminars on technology – andspecialized subjects, like stay cable seminarsfor instance – are the mainstay of the way inwhich knowledge is passed from BBR HQ tothe BBR Network. In 2011, nearly 100delegates came to the BBR regional training

seminars – and a few dozen more attendedsessions held locally, at the franchisees’offices.The creation of the BBR Factory ProductionControl and BBR E-Trace has revolutionizedthe way in which BBR technology ismanufactured, procured and distributed tothe highest quality standards, while offeringwhole life traceability. It is being furtherdeveloped to become an ‘exchangedatabase’ so Members will be able to seewho is doing what.

SETTING NEW BENCHMARKSAt BBR HQ, we do realize that manydevelopments have been introduced at whatmay seem like lightning speed to somepeople in the construction industry.Therefore, our emphasis will be on creating adeeper understanding of the wide range ofpossibilities open to BBR Network Members.So, now we will be further investing intraining, sharing resources and networking.

TALKING BBR

Advantages of the BBR Networkfranchise systemu Latest internationally approved PT and stay cable technologyu Professional marketing and communication toolsu Technical, commercial and project specific supportu Leading edge supply chain and quality management systemsu Regular regional and local training seminarsu Knowledge transfer, global and regional forums and conferencesu International collaborations and alliances for large or special projectsu Recognized global brands and trademarksu Proven franchise system, backed by a continuously advanced technology for over 65 years

u Strong local roots and highly qualified professionals for highest customer servicebacked by a global enterprise – the BBR Network

Without doubt, before we are celebratingthe first decade of the BBR Network, we willsee an even greater number of joint venturesbetween Members to realize some of theworld’s largest and most challenging projects.We will also see a market place which, withthe help of the BBR Network, fullyappreciates the complete spectrum ofofferings – in terms of BBR technologies,know-how and customized service for ourclients – that we can provide. l

8 CONNÆCT

Recent developments include the innovative BBR HiEx CONASaddle which is already being used for two major bridges and, inaddition, we have secured European Approvals for our CONA CMFand CONA CMM Single post-tensioning technology.

STAY CABLE CONNECTIONSStay cables are connected to the pylon using standard anchorages orsaddles. Saddles offer designers various advantageous options – suchas a better arrangement of cables at the pylon and reduced pylondimensions. However, standard saddles, either friction or shear key,exhibit some significant drawbacks, which discourage their use:u Load carrying elements cannot be inspected or replacedu Slippage when faced with moderate differential forcesu Fretting fatigueu Strand installation and removal/replacement is either limited orimpossible

BBR HIEX CONA SADDLEThe BBR HiEx CONA Saddle is the latest saddle approach for cable-stayed and extradosed bridges which completely eliminates the pro-blems associated with standard friction saddles. This modern saddleconcept replaces the standard friction saddle or shear key with apost-tensioning saddle, thus creating a compressive concrete environ-ment and providing a fixed point for the stay cable at the pylon.

MONOTUBE APPROACHThe standard configuration for the BBR HiEx CONA Saddle consistsof a parallel arrangement of individual guiding systems surrounded bya high strength grout – all enclosed in a curved smooth steel pipe.Seven-wire HDPE-sheathed prestressing steel strands – factoryprovided with corrosion protection filling material – are insertedthrough the guiding system and connect coupler heads placed atboth sides of the pylon. While the high strength grout provides a stiffenvironment, strands are fully replaceable as there is no bondedconnection between the guiding system and external HDPE of thestrands. The minimum radius of this saddle configuration is up to 2.0 m.

FULL BUNDLE APPROACHAlternatively, a bundle of bare strands fully bonded to the pylon might also be used, if permitted at the place of use. The minimum radius of this saddle configuration depends on the degree of filling and maximum contact pressure permittedat the place of use.

BBR VT International’s Research & Development(R&D) and Engineering team, led by Dr.Antonio Caballero, is continuously reviewing,

testing and developing ways to refine and enhanceBBR technology, ensuring that the BBR Networkalways has access to the latest and best constructiontechnology.

Latest BBR technology

THE BBR HIEX CONASADDLE IS THE LATESTSADDLE APPROACH FORCABLE-STAYED ANDEXTRADOSED BRIDGES

“”

Benefits of BBR HiExCONA Saddles

u The stay cable technology, used on leftand right stay cables, is proven andtested according to fib and otherrecommendations.

u The saddle is equipped with testedand European approved post-tensioning technology.

u The entire differential force is fullytransferred without saddle slippage.

u Post-tensioning force at the saddle ishigher than maximum service load atthe stay cable, which eliminates axialfatigue and fretting fatigue on thesaddle.

u The compressive environmentprevents tension cracks and enhancescorrosion protection.

u Inspection, replacement and strand-by-strand cable installation are allpossible.

u Corrosion protection is greater than inconventional saddles with up to fivecorrosion barriers in the standardconfiguration.

u During maintenance/replacementoperations, only replacement of theaffected stay cable on one side of thepylon is required – and not the fulllength. Replacement is even easierbecause tensile elements, which need tobe removed, do not cross the pylon.

9CONNÆCT

STAY CABLE AND SADDLECONNECTIONThe BBR HiEx CONA Saddle and BBRHiAm CONA stay cable are connectedthrough a coupler sleeve, the BBR HiExCONA Sleeve-W. Both the post-tensioningcoupler head of the PT saddle and the nuthead of the stay cable are threaded into thesleeve coupler. The CONA Sleeve-Wincorporates two lateral windows to allowwedge inspection, strand-by-strandinstallation and cable replacement.

SADDLE FATIGUE TESTINGThe HiEx CONA Saddle has been tested forboth ultimate axial transfer loading andfatigue with subsequent loading. Fatiguetesting was carried out to an axial stress-range of 200 MPa for 2,000,000 load cycleswith anchorage rotations of 0.6° at an upper

TALKING BBR

axial load of 55% GUTS, which covered bothfib and CIP specifications for stay cable andextradosed applications. After fatigue testing,the BBR HiEx CONA Saddle was axiallyloaded to 100% GUTS, while state-of-the-artrecommendations only require 95% GUTS.

NEW INTRODUCTIONSBBR VT International has introduced twonew European approved post-tensioning kitsfor special flat slab applications.

CONA CMF FLAT SYSTEMThe new BBR VT CONA CMF BT containsthe latest post-tensioning technology for flatslabs requiring PT tendons with 02 to 04

strands. The new system is based on 0.5’’ (93 mm2 and 100 mm2) and 0.6’’ (140 mm2 and 150 mm2) standardprestressing strand or monostrand.The new flat bearing trumplate has anoptimal rectangular outer shape, whichallows it to be installed in the thinnest slabs.Three different planes, whose slendernesshas been designed to reduce the peak of thebursting stresses, transfer the load to theconcrete and allow for full stressing at verylow concrete strength.The anchor head is in a separated body andcommon to the CONA CMI family, bringingreliability and competitiveness to the system.The CONA CMF system has been testedagainst static load, fatigue load and loadtransfer to the structure. The system fullycomplies with the Technical ApprovalGuideline ETAG 013.

CONA CMM SINGLEThe CONA CMM family, exclusive forunbonded tendons, has recently beenextended with the CONA CMM Single forbonded applications. The new post-tensioning system is now also available withsingle 0.6’’ (140 mm2 and 150 mm2) standardprestressing strand for bonded applications.The system can be used in combination withround corrugated steel or plastic ducts. Thenew development has also required somegrouting tests which have shown verysatisfactory results in all critical locations,such as the wedge area and couplers. l

10 CONNÆCT

This three day event began in traditionalstyle with a Charity Golf Day which raisedCHF4,000 for the Kantha Bopha charitablechildren’s hospital foundation in Cambodia. In the evening, delegates took a boat trip onLake Lucerne to catch their breath andexchange news together. The next day,Marcel Poser gave an opening addressmarking the start of the formal part of theconference.

SHARING INTERNATIONAL KNOW-HOWDelegates had the opportunity to hear firsthand about the construction of the iconicKuala Trengganu footbridge from Yok-LinVoon of BBR Construction Systems Malaysiaand about external prestressing in Polandfrom BBR Polska’s Jacek Sowa.

SPECIAL GUESTOur guest presenter this time was LuisCancio, J L Cancio Martins StructuralEngineers who shared his experiences onthe subject of ‘PT bridge design with BBRtechnology’.

BBR TECHNOLOGYA review of the state-of-the-art BBR VTCONA CMX post-tensioning technologywas presented jointly by Antonio Caballeroand Mathias Gallati. Later, Antonio also gave a presentation entitled ‘BBR HiAm CONA –superior stay cable technology’.

WORK WINNINGThomas Richli led sessions on efficientprocurement within the BBR Network andbridge construction networking. Meanwhile,

delegates heard about latest developmentsand plans for BBR E-Trace and the newcorporate BBR website from PiotrKrawczonek & Chris Roost and ValentinaMihajlovic & Daniel Senn respectively.

DISCUSSION FORUMSAs well as many opportunties to raisequestions and topical issues throughout theconference, a marketing and productionforum and the closing technical discussiongave delegates the chance to both seeksupport in specific areas and offer their inputinto future initiatives.

GLOBAL BBR CONFERENCE 2012Our next conference will be held on BintanIsland, Singapore in early March. l

In May 2011, the annual BBR Global Conference came hometo Switzerland – the country of its birth. Delegates fromevery corner of the globe converged on beautiful Lucerne

to learn, share – and enjoy!

BBR Project of the Year 2011

This time around, therewere a huge number ofprojects which

demonstrated the excellence ofBBR technology and theNetwork. However, twoprojects in particular capturedthe attention of the judgingpanel, so a joint award wasmade this year to BBR Polska –for the Krakow Footbridge and Warsaw's Temple of DivineProvidence.Although very different in nature, the complexity of theconstruction involved in both of these projects – and thehighly competent way in which BBR Polska rose to meetthe challenges – demanded recognition. Through these two projects, the consistent achievement ofhigh technical standards within the BBR Network can beappreciated by construction customers around the globe. Other award winners included Structural Systems Africafor Best CONNAECT Article for Building launch bridges in Southern Africa – their engagingarticle placed the project well in its local context and conveyed the technical expertiseand spirit with which it was completed. Spanish BBR Network Member, BBR PTE, wonthe prize for Best CONNAECT Photography for the material illustrating Vital link, theirarticle about the River Ebro Bridge project in Tarrgona, Spain. Finally, a special InnovationAward was presented to Structural Systems who, as well as taking on some of theworld’s most technically complex and challenging projects, are consistently ‘early adopters’of new BBR systems and techniques.

Coming home

11CONNÆCT

Just a few meters away from Corsica's famous medieval Louis XVI stylebridge, built during the Genoan occupation of the Mediterraneanisland, a dramatic new bridge is now set to take its own place in history

over the River Tavignano. Claude Neant of French BBR Network Member,ETIC, provides an overview of his company’s role in the creation of thisnew landmark. g

BRIDGES

ALTIANI BRIDGE, CORSICA, FRANCE

HistoricLANDMARK

12 CONNÆCT

This structure was erected over the river in phases and wasconcreted in-situ using a variety of formwork and scaffolding. As theRiver Tavignano can sometimes be very dangerous, construction wasprogrammed to take place between spring and winter, when thewater level in the river is low.

ALTERNATIVE SOLUTIONETIC proposed an alternative solution for the arch bearing. Eachbearing in the original design – comprising one steel lineararticulation joint – has been exchanged for four pot bearings installedside-by-side between two plates. This way, if necessary, the bearingscan be replaced as part of any future maintenance operations.

PT PROCEDURESThe post-tensioning was designed in accordance with the variousconstruction stages.After concreting the two lateral spans between the first abutmentsand the second piers on either side, we stressed the first group ofeight BBR VT CONA CMI 1206 tendons which were to be coupledfor the next phases. The remaining 12 tendons awaited final stressing.Next, the first half of the arch – from the left bank to where it joinsthe slab – was erected with BBR VT CONA CMM 0406 tendons.After this, the other half of the arch was constructed.Five special jacks were then installed, on temporary steel supports,between the two sections of the arch and on top, connecting withthe bridge slab.

SPECIAL FORMWORKWhen the load had been transferred to the five jacks, we set out thespecial formwork for the arch. After checking the arch displacementand the corresponding pressure, the jacks were fixed down.Next, we installed the formwork for concreting the two lateral spansof the arch and placed the tendons for these.After concreting the two lateral spans, we prepared the CONA CMM 0406 tendons on the top of the arch to assure theircontinuity before concreting the corresponding part of the slab andarch.We then performed a horizontal load lifting operation with the fivejacks on the top of the arch and we placed the formwork support. Inthis operation, the two parts of the arch had to be displaced byapproximately 30 mm.The arch was held in this position and the space between the twoextremities of the arch were connected with the slab, then afterinstallation of special formwork, it was concreted. For this concretingoperation, the five jacks were installed on a special recess.The load on the jacks was released by cutting the temporary steelsupport installed below the jack and the recess was concreted.We then stressed the first phase CONA CMI 1206 tendons in the slab with couplers at each end forcontinuity.The formwork on the lateral span of the arch was released andstressing of the CONA 0406 CMM tendons in the arch took place.Finally, we carried out the installation, tensioning and grout injectionof the last tendons – which were 116 m long – for continuity of thedeck slab.

CONNECTING CHALLENGESThe main challenge for us was the connection between the post-tensioned arch and the longitudinally post-tensioned thin slab – thelatter being only 60 cm thick.The stage where load was transferred using jacks – including the

The new Altiani Bridge lies between the towns of Aleria andCorte and spans the River Tavignano, in northern Corsica.The architecture of the historic bridge influenced thearchitects for the new bridge, Lavigne et Cheron and the

renowned structural engineer Michel Virlogeux, in collaboration withSECOA, all of whom also visualized an arch bridge, but with a fewmodern alternatives – such as post-tensioning in the slab.The 12 m wide deck slab is very thin – it is just 60 cm thick,increasing to 80 cm where the arch joins the slab. There are twolateral spans – of 15 m and 17 m long – either side of the 56 m longcentre span which connects with the central arch.The arch is designed with a cross-section of 2.4 m by 0.5 m abovethe foundation and this divides into two parts just before theconnection with the bridge slab.

13CONNÆCT

installation of scaffolding formwork andconcreting of the corresponding joint wherethe arch and slab connect – was also one ofthe main issues of the original design. Theoriginal design made it necessary to releasethe jacks without any chance of increasingthe first calculated pressure, due to theconcreting of this gap with reinforcementbars.

However, our alternative solution made aneffective load transfer achievable – byinstalling temporary steel support betweenthe jacks and the arch section. With ouralternative method, the transfer of load wasnot only possible, but also made very easy –we simply had to cut the special temporarysupport which had been designed and

fabricated from very thin steel plate.This was a technically demanding task in anycircumstances, however, we should alsomention the dangers presented by the smallriver – the Tavignano – which was subject toflash flooding. The river levels in this area ofCorsica can rise very high very quicklybecause of rainfall or melting snow, riskingthe uplift and collapse of the arch underconstruction before it had been concretedtogether with the deck slab. As with manyconstruction projects, timing – and goodplanning – is everything! l

BRIDGES

TEAM & TECHNOLOGYOWNER Collectivité Territoriale de Corse (CTC)

MAIN CONTRACTORJV – CARI, TERRACO & ETIC

ARCHITECT Lavigne et Chiron

DESIGNER Michel Virlogeux, SECOA

CONSTRUCTION DESIGN COGECI

TECHNOLOGY BBR VT CONA CMI internalBBR VT CONA CMM monostrandSpecial pot bearingExpansion joint

BBR NETWORK MEMBER ETIC S.A. (France)

Facts & FiguresBRIDGE DECK SLAB:

20 x BBR VT CONA CMI 1206cement grouted tendons

115 m long

33 t prestressing steel

2 x 20 anchors

2 x 8 couplers

CENTRAL BRIDGE SPAN ARCH:

2 x 18 BBR VT CONA CMM unbonded 0406 tendons

33.25 m long

6 t prestressing steel

SPECIAL POT BEARING FOR ARCH BRIDGE:

4 x fixed 3,000 KN pot bearings foreach foot of arch to reduce width inaccordance with arch section

THE MAIN CHALLENGEFOR US WAS THE CONNECTIONBETWEEN THE POST-TENSIONEDARCH AND THE LONGI-TUDINALLY POST-TENSIONEDTHIN SLAB – THE LATTER BEINGONLY 60 CM THICK.

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14 CONNÆCT

In just a few years, the number of peopleusing Malaga Airport had nearly tripled andthe increased traffic led to the extension andcomplete refitting of the airport. Meanwhile,on the outskirts of the airport, there is alarge continuously developing industrialcentre and an urban area which is alsoexperiencing significant expansion.

DIRECT ACCESSThese circumstances made it imperative thatthe Ministerio de Fomento launched this

project to support the airport with animportant new direct access. Thus, the‘Acceso Sur al Aeropuerto de Malaga’scheme was born.The need to avoid interference withsurrounding airport areas or existinginfrastructure dictated that the new accessroute should be an elevated structure ofconsiderable length – with connections atthree levels, formed by four branchesconnecting to the A7 – MediterraneanHighway.

WIDE IN-SITU DECKThe new structure is almost 2,500 m longand has the widest in-situ concrete deckconstructed in Spain by FCC. The standardspan between pillars is 40 m, expanding toreach 47 m at some points. Given the lengthof the deck, joints were installed at every160 m – four spans – at one fifth of thespan, the point where bending moments arealmost zero. The transversal section has an11.5 m wide and 1.6 m high cast in-situ post-tensioned slab.

ONE MILLION KILOS PT STEELFor this structure the post-tensioning is thekey player. Up to 12 tendons with 3106strands were installed during various phases,which brings the total amount of steel usedto more than a million kilograms

From Malaga on the Costa del Sol – the land of beaches and sun, a favorite tourist destination in Andalucia – Piedad Lucas of BBR PTE reports on an ambitious project. Malaga Airport is to

have an independent and important new access, allowing tourists fromaround the world to travel easily into one of Spain’s most friendly andcomfortable regions to live.

Gateway to the sunMALAGA AIRPORT SOUTH APPROACH, ANDALUCIA, SPAIN

15CONNÆCT

– and we used over 900 CONA CMIanchorages and couplers.Post-tensioning has also been used to solvespecific issues on this project – for example,transverse beams and the linking of fourprefabricated beams to pillars with cast in-situ spans.One of the major challenges on this projecthas been making the connections to existingroads with only minimal interruptions totheir heavy traffic flows. l

BBR Network Member NASA StructuralSystems was appointed to providespecialist post-tensioning services for threeroad bridges and two footbridges inEntertainment City by Hamad Bin KhalidContracting Co. WLL who are responsiblefor developing primary roads and utilitiesinfrastructure required for the new city.Entertainment City, being developed by AbuDhabi Investment House, is part of theLusail Development which is located alongthe sea shore on the outskirts of Qatar’scapital city of Doha. Lusail City is expectedto have 200,000 residents and host theopening ceremony, group matches and finalgame of the month-long FIFA 2022 FootballWorld Cup tournament at its 86,250-seatLusail Iconic Stadium. The five bridges were required to span overthe network of man-made canals. The roadbridges were comprised of in-situ post-tensioned ‘T’ girders of lengths from 22 m to25 m with in-situ reinforced concrete deck

slabs, while the pedestrian bridges werecomprised of twin cell cast in-situ box girdersof 25 m and 40 m lengths. We proposed andsuccessfully implemented solutions using BBRVT CONA CMI 1205 and 1905 anchoragesystems for all road bridges and BBR VTCONA CMI 1206 to 1906 anchoragesystems for the pedestrian bridges. Despite a significant track record, includingnumerous post-tensioned building projectsin Qatar, this project was very special to usas it was NASA Structural Systems’ firstbridge project in Qatar. l

BRIDGES

TEAM & TECHNOLOGYOWNER Entertainment City Qatar (Abu DhabiInvestment House)

MAIN CONTRACTOR Hamad Bin KhalidContracting Co. WLL

DESIGNER Associated Consulting Engineers

TECHNOLOGY BBR VT CONA CMI internal

BBR NETWORK MEMBER NASA StructuralSystems LLC (United Arab Emirates)

ENTERTAINMENT CITY BRIDGES, LUSAIL, QATAR

Five bridges in Qatar

TEAM & TECHNOLOGYOWNER Direccion General de Carreteras(Ministerio de Fomento)

MAIN CONTRACTOR FCC Construccion S.A.

DESIGNER INECO


BBR NETWORK MEMBER BBR PTE, S.L. (Spain)

FOR THIS STRUCTURETHE POST-TENSIONING ISTHE KEY PLAYER.“

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16 CONNÆCT

POZNAN WESTERN BYPASSThe bypass around the western city ofPoznan was constructed as part of the S11 express road dual carriageway – linkingPoznan to Koszalin, as well as the S5 expressroad, connecting Poznan and Wroclaw. Thetask was divided into several stages. The firststage was the 14.2 km long Zlotkowo-A2(Gluchowo) section which consisted of 14 viaducts, one bridge and twobicycle/pedestrian paths. This major projectcomprised the construction of severalstructures including seven post-tensionedflyovers, the launching of steel arches and theassembly of bearings and expansion joints, aswell as the prestressing of one overpass.

1 WARSAW SOUTHERN BYPASS S2 EXPRESSWAYThe Warsaw Southern Bypass project isthe S2 express way from Konotopa junctionto Pulawska junction, together with theexpressway S79-NS route section, linking theAirport junction to both MPL Okecie andMarynarska junctions. It includes 13 flyovers,two footbridges, a tunnel and 18 km of noisebarriers. This route extends toapproximately 10 km outside of Warsaw citycentre.We were commissioned for the prestressingof the large flyover – a complex construction,in a horizontal and vertical arc, with internaland external cables. We were also contracted

2

for the design and construction of reinforcedsoil walls with wall panels. In addition to this,we are to supply and install expansion jointsfor many of the other structures, as well as PT bars on a suspended pedestrian walkway.

A2 MOTORWAY BYPASS – MINSKMAZOWIECKI The Minsk Mazowiecki section of the A2Motorway Bypass is part of the E-30 road –one of the East-West Trans-European routeswhich is a direct continuation of this routebeyond Warsaw. It is the first section to becompleted east of the River Vistula. Sometime ago, we built two post-tensioned

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After many years of backlog in the construction of Polish road andbridge infrastructure – a legacy of the former communist system– clearing it is a current day necessity. Rapid infrastructure

development is still taking place in Poland, thanks to loans from theEuropean Union. BBR Polska now features in its portfolio a wide rangeof recent infrastructure projects, both large and small. Site Manager,Karol Bucholc who specializes in this field, has actively participated,together with his colleague Marcin Wyrczynski, in all of the projects andfrom an early stage.

INFRASTRUCTURE PROJECTS,POLAND

CLEARINGTHE

BACKLOG

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17CONNÆCT

structures on this stretch of road and, in2010 we received another contract as theproject was almost completed. It was for twoprestressed single-span structures forming amotorway viaduct with a span of about 40 m.We stressed the first structure in summer2011 and completed the second one justbefore the onset of winter. Completion ofthe entire route is scheduled for August2012.

NORTH BRIDGE ROUTE North Bridge Route is a 3.4 km long sectionof highway with a river bridge which,together with access roads, is the mainstructure of the North Bridge over the RiverVistula. Within the scheme, we have beencommissioned to prestress three structures,including a large flyover within ModlinskaStreet. It is one of the most anticipatedprojects in Warsaw, apart from the highwaybridge on the Warsaw Southern Bypass.

ARMII KRAJOWEJ ROUTE S8 INWARSAWThe section of the Armii Krajowej Routefrom Modlinska junction in Warsaw toPilsudski junction in Marki has beenupgraded to meet the parameters of the S8 expressway – a huge project, carried outin an urban area. It will greatly improvecirculation for local traffic and ease of transitfor vehicles passing through the city.Our task was to provide a total of 72 expansion joints for 26 structures. Alldeadlines were very tight. Despite someinitial challenges, we succeeded inmanufacturing and installing the devices oneach structure. We are particularly satisfiedwith our work on this project because itforms part of our route into the BBR Polskaoffice – we can now drive over our ownexcellent expansion joints!

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ZWIRKI 1 WIGURY STREETFOOTBRIDGEZDM, the Municipal Roads Authority inWarsaw, has embarked upon therenovation footbridges in the city. For oneof these, we created a suspension bridgeusing PT bars and this will be seen bymany foreign guests arriving in Warsaw asit passes over Zwirki I Wigury Street –named after two famous Polish pilots –and leads to Okecie Airport. This couldbe why city authorities decided to honorthe Polish heroes by creating a pylonshaped like a letter ‘V’ – for Victory.Banners welcoming visitors to the Euro2012 football championships have alreadybeen fixed onto the structure.

WIDAWKA RIVER BRIDGEDriving across Poland, one occasionallyencounters a detour or repairs being madeto local roads. The post-tensioned bridgeover the small Widawka river is one suchexample of a task being carried out on areconstructed provincial road. It is a smalltwo-spanned structure with two beams of atotal length of 48.4 m. We have deliveredand installed 12 BBR VT CONA CMI 1906PT tendons and six TOBE pot bearings forthe project. l

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TEAM & TECHNOLOGIES

BBR NETWORK MEMBER BBR Polska Sp. z o.o.(Poland)

OWNER General Directorate for NationalRoads and Motorways, Warsaw

OWNER Municipal Roads Authority, Warsaw

POZNAN WESTERN BYPASS

OWNER General Directorate for National Roadsand Motorways, Poznan

MAIN CONTRACTOR Skanska SA in consortiumwith INTERCOR Sp. z o.o.

DESIGNER Scott Wilson Ltd. z o. o., in partnershipwith ARCADIS Sp. z o.o.

TECHNOLOGY BBR VT CONA CMI internalExpansion jointBBR VT TOBE pot bearingLaunching

WARSAW SOUTHERN BYPASS S2EXPRESSWAY

MAIN CONTRACTOR Consortium of BilfingerBerger Construction SA, PRM Mosty-Lodz,INTERCOR Sp. Z o.o.

DESIGNER DHV Poland Sp z o.o., in partnershipwith BPBK SA

TECHNOLOGY BBR VT CONA CMI internalBBR VT CONA CME externalExpansion JointStay cable

A2 MOTORWAY BYPASS – MINSKMAZOWIECKI

MAIN CONTRACTOR Consortium led byConstruction Company Road and Bridge Sp. z o.o.

DESIGNER Tebodin SAP-Projekt Sp. z o.o.,DOPRAVOPROJEKT a.s.


NORTH BRIDGE ROUTE

MAIN CONTRACTOR Consortium: P.R.I. ‘Pol-Aqua’ S.A. Partners, Sando BudownictwoPolska Sp. z o.o., Construcciones SanchezDominiguez – Sando S.A. & Kromiss-Bis Sp. z o.o

DESIGNER Schüssler-Plan, bridge SC, SC OPTEM,TRANSMOST Sp. z o. o.


ARMII KRAJOWEJ ROUTE S8 IN WARSAW

MAIN CONTRACTOR J&P-AVAX S.A.

DESIGNER TRANSPROJEKT-WARSZAWA Sp. z o.o.

TECHNOLOGY Expansion joint

ZWIRKI I WIGURY STREET FOOTBRIDGE

MAIN CONTRACTOR WPM Mosty S.A.

DESIGNER WPM Mosty S.A.

TECHNOLOGY Stay cablePT bar

WIDAWKA RIVER BRIDGE

OWNER Local Management of District Roads,Lodz

MAIN CONTRACTOR INTERCOR Sp. Z o.o.

PLANT DESIGN & CONSULTING PRI Kepno


BBR VT TOBE pot bearing

1 2 3 4 5 6 7

2 3 5

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BRIDGES

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18 CONNÆCT

The tendons have been used tostrengthen a four-lane, 545 m longcantilever bridge that services one ofAuckland’s busiest arterial routes. TheTamaki River Bridge – known locally asthe Waipuna Bridge – crosses the TamakiEstuary and provides a vital link betweenthe city’s southern motorway and theeastern suburbs. The strengthening work complements amajor project being undertaken byTranspower, the owner of NewZealand’s high-voltage powertransmission network. The company isreplacing overhead power lines in thearea with underground transmissioncables and getting these across theestuary means stringing them throughthe centre of this busy road bridge.

EXTERNAL STRENGTHENINGOwing to the extra load these cables willimpose on the 37-year-old, precast, pre-stressed concrete bridge – and to ensurethat it continues to perform for themotorists that use it – we werecontracted to undertake the

strengthening work which uses BBR VTCONA CMB external band tendons.Tested and already approved and used inEurope, this post-tensioning system iseminently suitable for such externalapplications. Rather than being bondedto the structure, the band tendons wereinserted into the central void of thebridge’s box girder, transferring forces tothe structure via large steel anchoragebeams installed at the end of eachtendon.

STAGED STRESSINGAt the factory, the strands were greasedand individually sheathed withcontinuously extruded HDPE (high-density polyethylene). They were thengrouped in parallel and enclosed in arectangular extruded plastic sheath. Thiseliminated the need for grouting andprotects the strands against damage andcorrosion. Supplied rolled around largewooden reels, the tendons were thenwinched into the cavity of the boxgirder, then through the diaphragms anddeviators, before being stressed and

locked off. Great care was taken tostage the stressing operations to avoiddeveloping differential bending andtorsion loads between the two adjacentbox girders.

SAVINGS ALL-ROUNDThe system can be used with a broadrange of construction materials –including concrete, steel and timber –and allows for future re-stressing, de-stressing and replacement. It also makesit easy to undertake inspections andmaintenance, which means considerablesavings in time and costs.We worked closely with the BBRNetwork’s band post-tensioningspecialists to ensure the system wasinstalled to international best practice.This included valuable input fromMunich-based BBR Network MemberVorspann-Technik who assisted withspecific detailing and specialistequipment and methodologies, asdeveloped for similar projects in theirmarket. By the time the project wascompleted, the team had installed three 150 m long tendons into each cell ofthe twin box girders. Each tendoncomprises four layers of CONA CMBband, each containing four 15.7 mmdiameter strands and a capacity of3,200 kN per tendon. In order tofuture-proof the structure for whenadditional lanes are added, provision hasalready been made within the new endanchorages for the installation of 12 further CMB band tendons. l

TEAM & TECHNOLOGYOWNER Transpower

MAIN CONTRACTOR Fulton Hogan Civil

DESIGNER Beca Infrastructure

TECHNOLOGY BBR VT CONA CMB band

BBR NETWORK MEMBERBBR Contech (New Zealand)

The BBR Network Member in New Zealand, BBR Contech,has undertaken its first project using BBR VT CONA CMBband tendons – and it’s proving to be the ideal solution.

Their Project Manager, Hugo Jackson, describes the workassociated with the project.

THE IDEAL SOLUTIONNEW ZEALAND FIRST FOR BAND TECHNOLOGY

19CONNÆCT

Located between the Barton Highway and Glenloch Interchange and passing through the suburbs of Kaleen,Bruce and Aranda, the Gungahlin Drive Extension (GDE) project was undertaken by the ACT Governmentto accommodate the ever-expanding population of Canberra’s northern suburbs. Deirdre Allen of

Australian BBR Network Member, Structural Systems Limited, outlines the project and SSL’s work, as a specia-list bridge contractor to BMD Constructions, on the 108.5 m long bridge constructed over Belconnen Way.

BRIDGES

BELCONNEN WAY OVERBRIDGE, CANBERRA, AUSTRALIA

Value throughINNOVATION

The existing bridge at Belconnen Way was constructed during Stage 1 of the GDE and carried both the northbound and southbound lanes ofGungahlin Drive. As part of Stage 2, a new bridge was required alongside the existing to carry the two southbound lanes of the road uponcompletion of the extension works. The Stage 2 Bridge was to be identical both structurally and aesthetically to the existing bridge g

20 CONNÆCT

– a three span structure, formed with a single cell post-tensionedreinforced box section and a span arrangement consisting of a mainspan of 53 m with approach spans of 27.5 m each.

ALTERNATIVE METHODOLOGYThe initial proposal was to build the bridge using conventionalbalanced cantilever construction as this was the method used toconstruct the Stage 1 Bridge. This construction method would allowBelconnen Way to remain open for the extent of the works, howeverwould involve the use of a large formwork traveler which, for therelatively small main span, was cumbersome and slow to erect andrelocate. Also, an approximate break in program of 30 days would berequired to dismantle the traveler upon completion of the first half ofthe structure, then move and reassemble on the other side of thebridge, prior to recommencing production. After reviewing these drawbacks, we put together an alternativeproposal which involved constructing the end spans of the bridgeusing traditional formwork while utilizing a single formwork traveler –designed by us specifically for the project – to construct the mainspan. This solution would significantly reduce the size of the traveler,thus making it easier to move, assemble and operate. Furthermore, theproposal included constructing the first main span segment beyondthe pier using the traditional formwork, which ensured all thesegments to be constructed using the formwork traveler were ofequal segment depth for ease of construction and to reduce thecomplexities of the traveler.The proposal was presented to BMD and the considerable cost andtime saving benefits that accompanied this innovative approach led tous being awarded our first travelling formwork project in Australia.

IN FOCUS: Purpose-built formwork travelerThe formwork traveler consisted of two main components – the upper and lower assemblies – and weighed 52.5 tnominally, including the concrete counterweights, forms,platforms and barriers.The upper assembly was formed primarily of two 1200 mmmain beams – each sitting on two pedestals with 75 t rollersat the front and 20 t rollers at the back of the traveler. Threetransverse beams were positioned to run between thebeams at the front of the traveler and these supported thehanger bars carrying the segment formwork. This upperassembly ran on a guide rail pinned to the deck to ensurelateral guidance while the formwork was traveling.The lower assembly comprised the lower form, whichincluded the outer web and wing forms, and the inner form,which moved independently from the rest of the traveler.The outer web form and the wing form – all one section – were adjustable to allow for the 100 mm change in webthickness for some segments. There was also an allowancefor the form to be opened away from the poured segmentgiving the 50 mm clearance required to launch the travelerforward. This section was bolted to the lower form inwhichever position was required. The lower assembly wassupported by 44 26.5 mm bars connected to the upperassembly and to the previous segment, ensuring correctlevels could be obtained across the segment and continuityof profile throughout the bridge. Two 32 mm stress bars ran vertically through the mainbeams at the rear of the traveler, connected through acoupler to second bar cast into the bridge webs. Thesebars were stressed to 150 kN to counteract the concreteload while a segment was being poured. Once the concretehad reached strength, the bars were de-stressed andremoved to allow the traveler to be launched forward – and15 t of counterweights ensured stability during movement ofthe traveler.

BRIDGES

21CONNÆCT

SCOPE OF WORKSAlong with the design and supply of the formworktraveler, we were responsible for the supply andinstallation of post-tensioning materials, stressingand grouting of tendons, abutment jacking forbearing placement and supply of engineeringdesign support – including monitoring ofdeflections and precamber adjustment during theconstruction of the bridge. The alternative methodology we produced for theconstruction of the bridge required substantial re-engineering of the structure to allow for thechange in construction method and sequence.This bridge engineering service was also providedby us as part of our contract and included the re-design of the cantilever and post-tensioning. As part of the formwork traveler package,operational drawings and step-by-step instructionswere produced outlining the assembly andtravelling procedure for the main contractor. Weprovided supervision during the initial stages toanswer any queries or concerns regarding thetraveler operation and, over the course of project,members of our post-tensioning crew were onsite to provide any further assistance required.

PT INSTALLATIONThe post-tensioning for the bridge consisted ofBBR VT CONA CMI 1206 and 1906 anchorages.All of the tendons within the structure weredouble live and contained

15.2 mm diameter low relaxationstrand. On each side of the bridge, 20 12 strand tendons provided theprestress in the cantilever duringconstruction – the longest tendonwas 52 m long. Utilizing 80 1206anchorages, four tendons wereanchored at the end of eachsegment, up to the closing segmentof the main span. When thesegment had reached strength, thetraveler was launched forward forthe next segment pour and, in thisposition, provided a safe workingplatform over Belconnen Way forthe installation of the four anchoredtendons. These tendons were thenstressed from the anchoragelocated at the abutment end.Six 23 m long 12 strand tendonswere located through the end spans

to provide continuity stressing. Each tendon wasanchored at the abutment face and in blisterswithin the box at the other end, there were 241206 anchorages in total. As with the cantileverstressing, these tendons were stressed from theanchorage at the abutment. The continuity prestressing in the main spanconsists of 10 19 strand tendons – with 20 1906 anchorages located in blisters within thebox – the longest tendon measures 45 m. These tendons had to be stressed frominside the box and this, therefore, presented somechallenges in maneuvering the 1.1 t stressing jackand working within a depth less than 1,500 mm inthe main span segments. A chain block and pulleysystem was the final solution, with the stressingjack sitting on a basic trolley and the travelerpenetrations through the top slab of the deck –which, at this point, was not in use – utilized aslifting points to attach the pulleys.

UNCOMPLICATED VALUEWe were awarded the project on the basis of thesignificant savings our value engineering achievedfor the main contractor. Providing the travelerengineering, post-tensioning and bridgeengineering services in one package ensured theseintegral aspects of the works were fullycoordinated. Furthermore, our re-engineeringenabled a less complex construction method andfaster site progress to be achieved compared tothe initial concept. l

TEAM & TECHNOLOGYOWNER ACT Government

MAIN CONTRACTOR BMD Constructions

DESIGNER AECOM Australia Pty Ltd

TECHNOLOGY BBR VT CONA CMI internalBalanced cantilever

BBR NETWORK MEMBERStructural Systems Limited (Australia)

22 CONNÆCT

Polish BBR Network Member,BBR Polska has the majoraccolade of having worked

on the construction of the longestbridge in Poland. Jacek Sowa, theircantilever bridge specialist,provides a brief summary of thetwo year struggle to construct thenearly two kilometer long bridgein Grudziadz.

In October 2011 – three years after the firstspade of soil was dug – the 62 kmGrudziadz to Torun section of the A1Motorway was finally opened. A vital part ofthis new stretch of motorway is a bridgeover the River Vistula, near Grudziadz.

BRIDGE OVERVIEWGrudziadz Bridge consists of three sections.Firstly, the 988.8 m long longitudinallylaunched north overpass was constructed in43 sections and launched from one side.

Then, there was the main bridge which is athree span cantilever superstructure andfeatures a 180 m concrete span – the longestconcrete span in Poland. Finally, the projectincluded a 556.8 m long incrementally launch-ed overpass with 25 sections, each 24 m long.

CANTILEVER DESIGNAs one of the main subcontractors for thisstructure, we participated in the design ofthe cantilever section, supplied and servicedformwork travelers, supplied internal and

Po l a n d ’ s l o n g e s t b r i d g e

A1 MOTORWAY BRIDGE, GRUDZIADZ, POLAND

Local insight: Grudziadz Constructed from red brick some three to four hundred yearsago, the imposing buttressed granary buildings are one of the

best known features of Grudziadz. In bygone years, as well asserving as grain storage space, these ancient structures – some ashigh as seven storeys – were also used as part of the city’s defensesagainst invaders.Grudziadz first appears in written documentation in the 11thCentury and, in 1522, it was here that Nicolaus Copernicus famouslypresented his thesis on monetary systems. By the end of the 19thCentury, the city had established a power and gas plant, water andsewerage systems, a street tram network and a number of majorindustrial plants.The city’s geographic location – on the banks of the mighty VistulaRiver and on trading routes – ensured Grudziadz would thrivecommercially. Today, the city has a population of over 100,000 peopleand specializes in metal, chemical, construction and light industry.

BRIDGES

23CONNÆCT

external stressing technology – the latteramounting to a total of 2,275 t of steel. Finally,we also supplied modular expansion joints –the largest of which had a 900 mm gap.

SPEEDING PROGRESSOriginally, it had been planned to build thetwo carriageways separately, but many delaysforced the main contractor to speed upworks and build all three sections at thesame time. We provided 25 staff, supervisedby two engineers, who worked continuouslyfor a whole year. Despite heavy winters,unexpected floods and the tight schedule, weonce again proved that our team is the bestfor this type of work in Poland. Meanwhile,our colorful form travelers – eight sections,each in a different color – are now storedand waiting for a new challenge! l

In total, this new road section is about2,000 m long and the Donaukanal, aninland waterway through Vienna – built140 years ago, during Danube regulationworks – had to be crossed.This bridge was designed as an integralbridge without moveable bearings andbuilt in three stages. The two side spansare each 32 m long and the mid span is65 m, giving a total length of about 130 m– and, with a width of 15 m, there will beplenty of room for vehicular traffic, as wellas pedestrians and cyclists. It is a veryslender, elegant construction, with twopairs of steel columns in each of the four

steel casting knots – two on eachriverbank.After erecting the two side spans, the midspan had to be constructed with nointerruption to normal river traffic –which, amongst other river-users, includedthe Twin City Liner, a high speedCatamaran connecting Vienna andBratislava.For the post-tensioning, we used the BBRVT CONA CMI 1206 system and afterstressing, all deformation in the deck wasfrozen off. All the challenges of design andconstruction – such the as disconnectionof dams and abutments, bored piles withelastic foundations and even moveableduct-joints for the PT system – were atlast resolved. l

Vienna Harbor, located to the east of the city, is a dynamic and growingtransfer site on the Danube River in Austria. To ensure an optimizedtransport connection with the road linking to the nearby A4 motorway –

the main connection to Slovakia and Hungary – a new route has beenconstructed. Norbert Bogensperger of Austrian BBR Network Member, Vorspann-Technik provides a brief insight into the project.

TEAM & TECHNOLOGYOWNER Gdansk Transport Company

MAIN CONTRACTOR SKANSKA NDI

DESIGNER Wanecki Sp. z o.o. Firma ProjektowaBBR Polska, in collaboration with CEPAS,Switzerland

TECHNOLOGY BBR VT CONA CMI internalBBR VT CONA CME externalBalanced cantileverExpansion joint

BBR NETWORK MEMBERBBR Polska Sp. z o.o. (Poland)

TEAM & TECHNOLOGYOWNER MA 29, Magistrat der Stadt Wien

MAIN CONTRACTOR STRABAG SE

DESIGNER pcd-ZT GmbH


BBR NETWORK MEMBERVorspann-Technik GmbH (Austria)

Resolving challenges

SEITENHAFENBRÜCKE, VIENNA, AUSTRIA

WE PROVIDED 25STAFF, SUPERVISED BY TWOENGINEERS, WHO WORKEDCONTINUOUSLY FOR AWHOLE YEAR.

“”

24 CONNÆCT

The new bridge over the RiverPisuerga in Valladolid, was

inaugurated in Spring 2011. Alsoknown as Santa Teresa Bridge, itnow links the neighborhoods ofRondilla and La Victoria. Jose LuisPlaza of BBR PTE, the BBRNetwork Member in Spain, reportsthat construction work, performedby FCC and Isolux in joint venture,was completed in 14 months to abudget of €14.7 million. This bridge connects Rabida and PesetaStreets and is 28.3 m wide. It has:u Two 3.5 m wide vehicle lanes, with 2.4 mwide planters on either side to separatethe traffic from the pedestrian zone

u A 3.2 m wide bicycle lane.u Pedestrian sidewalks of 5 m and 8 m.wide, with glazed railings.

The contract also included the developmentof the adjoining streets and three new round-abouts to absorb the traffic generated by thenew infrastructure – and future develop-ments planned for the northwest of the city.

ENVIRONMENTAL STUDYBefore starting work, an environmentalimpact study was carried out into the effectsthat construction might potentially have onthe species of the area. As a result of this,the optimal timing for the works wasestablished as being spring and summer,when the effects on the local wildlife wouldbe lessened.

BRIDGE DESIGNThe 194 m long bridge, which has fourintermediate piers, is divided into fivecontinuous spans – 19 m + 25 m + 30 m +90 m + 30 m – the 90 m span crosses theriver. The double cell box girder is of variableheight.

PISUERGA RIVER BRIDGE,VALLADOLID, SPAIN

Mixedtendontactics

25CONNÆCT

INTERNAL & EXTERNAL PTThis project was executed using BBR VTCONA CMI and CME 2406 and 2706systems, with stressing and fixed anchoragesat both ends. The whole structure containsaround 102 t of 15.2 mm diameter post-tensioning strand.Spans 1 & 2: These are concrete structureswith corrugated steel sheaths. Here, some ofthe PT tendons are linked to the next spanwith couplers. We used some tendons with24 strands and these run in a 110 mm innerdiameter sheath. The remaining tendons,which contain 27 strands, have couplers inthe section between piers 1 and 2 and arecontinuous in the next span.Spans 3 & 5: These are of composite steeland concrete construction. The first part isconcrete and the next steel, with concretetop and bottom slabs. For these spans, weused 27 strand tendons. The first part of thetendon sheath is a 128 mm inner diametersteel strip. Some tendons make the transitionto a 140 mm outer diameter polyethylenesheath within the concrete section, ending inexternal metal trumpets supported againstthe steel frame. There were also newtendons in this span with fixed anchorages inone of the end tendons.Span 4: Essentially, this is a metal box with aconcrete top slab and was not post-tensioned.

MIXED TENDONSSeveral tendons were housed in a metal stripsheath in the concrete section and inpolyethylene within the steel section, in Span 4. Before concreting the first section, apolyethylene sheath was left protruding fromthe concrete. This was stretched until longenough to allow mirror welding later and didnot protrude so far that it was in the way of

setting up work for the next steel spansection.Special care was taken in supporting thesheath and attaching it to the stretchers, aswell as taping the joints – because theinstallation of tensile elements only took placeafter concreting. At the high point of thepolyethylene sheath, a drain was installed –and was well taped to keep out concrete.After the steel box sections were placed intheir final positions in both sides of the centralspan, we were able to complete tendonassembly. Metal trumpets were placed againstthe steel sections, after which we took care tomeasure very accurately the remaining lengthof polyethylene sheath required – we

assumed the ends would have welded stubs.Once this polyethylene section wasprepared, it was welded to the protrudingsheath – from the previous section – andthen, using a metal ring, it was screwed tothe trumpet at the end of the stub. Beforefixing, a bead of silicone was applied to thesurface facing the trumpet stub to improvesealing.The placement of the metal trumpet wasdone with much care, bearing in mind thatpurging would be carried out in an upwardsdirection. Each trumpet has two stops thatwere placed against the brackets welded tothe sides, so that they were set against themetal frame at the point where the sheathswere joined.

STRESSING OPERATIONSTo balance the forces introduced during thepost-tensioning process, some tendons hadto be stressed using two multistrand 750 thydraulic jacks which were connected with aunique hydraulic pump. Stressing was carriedout using both jacks at the same time andcompleted symmetrically in respect to theaxes of the two concrete boxes.In the abutment, we installed two 50 mmdiameter PT bars which were stressed totransmit retaining vertical and horizontalforces between the deck and abutment. l

BRIDGES

TEAM & TECHNOLOGYOWNER City Council of Valladolid

MAIN CONTRACTOR UTE FCC Construccion+ Isolux Corsan

DESIGNER Arenas & Asociados

TECHNOLOGY BBR VT CONA CMI internalBBR VT CONA CME external

BBR NETWORK MEMBERBBR PTE, S.L. (Spain)

THE WHOLE STRUCTURECONTAINS AROUND 102 T OF15.2 MM DIAMETER POST-TENSIONING STRAND.”“

26 CONNÆCT

The bridge configuration was 27.6 m + 52 m+ 27.6 m and the main challenge of thisproject was to decide on a goodconstruction method – as the consultant’sdrawing specified neither the method, northe sequence of construction. Initially, ourclient proposed to construct both side spanson heavy duty scaffolds. After stressing thecantilever tendons, the formwork and allscaffolds were to be maintained untilconstruction of the middle span over theriver had been completed. The six pre-castpost-tensioned I-Beams for the center spanwould be launched from a temporarilybackfilled access road. Next, the two stitchinggaps between the main span and side spanswould be cast. Finally, the continuity tendonswould be stressed from abutment-to-abutment and all the formwork and scaffoldsat side spans removed.

PRACTICAL METHODOLOGYBy introducing a 1905 BBR Type K coupler,the continuity tendon temporarily became asingle parabolic span tendon within the sidespan. When stressed, it was able to supportthe weight of the 27.6 m side span beams.Therefore the props and formwork could beremoved and reused on the other side span,generating savings in the cost of formworkand props.The cantilever tendons over the top of pierswere also stressed to hang the three

temporary steel trusses for in-situ casting ofthe central span beams. Each beam was castand its span tendons stressed beforeproceeding to cast the next beam, as thetrusses could only support the weight of oneconcrete beam. Next, strands were threadedinto the continuity ducts and coupled to theType K coupler anchor heads. Then the two1.4 m long stitching gaps were cast. Uponcompletion of stressing the continuitytendon, they were equivalent to theconsultant’s original design.

DESIGN CHECKAnalysis was carried out to check the bridgesuperstructure design at each constructionstage to ensure the proposed constructionmethod was safe and did not overload thecapacity of constructed elements and thatthe temporary structure would be stable.Complete bridge modeling, using Finite

Element Method (FEM), was used tosimulate the actual behavior of bridge atevery construction stage. Elastic springs –taking compression forces only – werecreated to model support scaffold legs. Also,the concrete stresses were checked forcompliance with the allowable limits.

DEFLECTION CONTROLIn this particular project, the final bridgeprofile had to be controlled to within +/-15 mm. We were also engaged toperform the deflection control duringconstruction. Total deflections at each construction stagewere estimated from the bridge model –with a timeframe specified by the client – topredict the behavior of the bridge duringconstruction. Then pre-camber values wereproposed, based on the total deflectionestimated, to achieve the final bridge profile.With BBR Type K couplers, our clientmanaged to construct the bridge using onlyone set of scaffolding and formwork for thetwo side spans. By working closely with theirtemporary works designer, they were able toconstruct the middle span safely andeconomically. Finally, our client also benefitedfrom the BBR Network’s constructionengineering and deflection control. l

The proposed highway alongBeluru, Long Teru and LongLama crosses the Teru River,

opening up interior rural areas fordevelopment. Originally, BBRConstruction Systems Malaysiawas contracted to carry out thepost-tensioning works for the newriver bridge – however, to improvebuildability of the bridge, theirscope was extended to includeconstruction engineering.Engineer Yan Man Chung des-cribes how this is being achievedby modeling the structure usingFEM, simulating the stressingsequence and with the applicationof BBR Type K couplers.

Engineering for buildability

SUNGAI TERU CROSSING, MIRI,SARAWAK, MALAYSIA

TEAM & TECHNOLOGYOWNER Public Works Department, Malaysia

MAIN CONTRACTOR Cityon Development Sdn Bhd

TECHNOLOGY BBR CONA internal

BBR NETWORK MEMBER BBR ConstructionSystems (M) Sdn Bhd (Malaysia)

27CONNÆCT

BRIDGES

ODRA VIADUCT, ZAGREB, CROATIA

Ramping upat Odra

TEAM & TECHNOLOGYOWNER Hrvatske Ceste d.o.o.

MAIN CONTRACTOR Zagorje Tehnobeton d.d.

DESIGNER Jadranka Ivkovic, IGH Zagreb


BBR NETWORK MEMBERBBR Adria d.o.o. (Croatia)

TEAM & TECHNOLOGYOWNER ASFINAG (Austrian NationalMotorway Authority)

MAIN CONTRACTOR STRABAG SE

DESIGNER KMP ZT GmbH



The Odra Viaduct is a part of the connectionramp for the Zagreb-Sisak motorwayinterchange in Odra. Damir Pavicic of BBRAdria explains that this ramp viaduct is 390 m long and was built in three partsusing traditional formwork and scaffolding.The second part crosses the motorway andrailway tracks and, because of its larger spans,it had to be prestressed. This part of theviaduct is 125 m long and 7.76 m wide withspans of 21 m + 3×28 m + 20 m. It has a120 cm thick cast in-situ prestressedreinforced concrete slab with side cantileversof variable thickness. BBR VT CONA CMI 1906 tendons connecttwo spans alternately with four tendonsstressed in each span. The total weight oftendons installed is 23 t and we used 32 BBRVT CONA CMI 1906 anchors. All workswere finished in just two months. l

After 50 years of intensive useand steadily increasing load,the life cycle of the twin-

arched Traunbrücke bridges atSteyrermühl has ended. Constructionis now underway to replace thesebridges which support the twocarriageways of the Vienna-Salzburgsection of the A1 Motorway.So that traffic flows can be maintained onthis important East-West connection, thetwo bridges are being constructedconsecutively. Work started with thespectacular blasting of the Salzburgcarriageway down into the Traun river. After erecting the first pier on the westbank, the operation was repeated on theeast bank for the second pier – then thefree cantilevering of eight segments began.Together with the two foreland bridges, theoverall length of the new bridge is around240 m and, with a deck width of 12.75 m –instead of the 11.50 m offered by theprevious viaduct – greater comfort and

enhanced road safety will be assured.The post-tensioning was designed with BBR VT CONA CMI 1206 and 0906 andcarried out by BBR Network Member Vorspann-Technik. Grouting according toEN 445-447 was executed for the firsttime in Austria. Within 13 months of the demolition of theold carriageway, the new bridge opened fortraffic and the construction cycle startedagain. By summer 2012, when bothcarriageways will have been rebuilt, thegeneral renewal of the 300 km long A1 Motorway – which has taken 15 years– will almost be finished. l

CantileveringFOR COMFORT

TRAUNBRÜCKE, A1 MOTORWAY, STEYRERMÜHL, AUSTRIA

28 CONNÆCT

The new bridge over thevalley in Santander’surban park – Parque Las

Llamas – now connects the cityon either side of this wonderfulgreen space. With its specta-cular white concrete bowstringarch, the bridge is destined tobecome an architecturalhighlight of Santander. JoseLuis Plaza from BBR NetworkMember, BBR PTE, reviewsthe construction project.

The Parque Las Llamas continues togrow, with a further 5,000 m2 beingincorporated into this 300,000 m2

green swathe which stretches from theEstadio Sardinero sports stadium to thenew bridge. The park grows under andaround the bridge and features smallprivate farm buildings – adjoiningprivate land will, eventually, become part

of a great park of a million squaremeters or more.The new bridge itself has, as anticipated,not only made a favorable impressionon the local landscape, but has also

immediately become a vital piece ofinfrastructure. In addition to providingan aesthetic reference point, in a city ofotherwise unremarkable architecture, ithas rectified the lack of interconnectionbetween two key areas. The north sideof General Davila, which is behindAvenida de Los Castros, the physicalborder with the valley of Las Llamas, is

now connected with the new residentialneighborhoods of Valdenoja, Cueto andMonte, where 6,000 homes have beenbuilt in the last decade and also withthe S20 motorway which borders thevalley.

DESIGN & CONSTRUCTIONBoth the nerve center of the deck – thewhite concrete arch – and the foot ofthe bridge were constructed in-situ,while the sidewalks and walkways wereprefabricated and assembled on site. Intotal, 86 pieces weighing 13 t each, weretransformed into a 23.6 m wide bridgewith two sidewalks, two vehicle lanes ineach direction and a bicycle lane in thecenter.This new arch bridge has been post-tensioned with 12 longitudinal BBR VTCONA CMI 1906 tendons made of 15.2 mm diameter strands and features32 mm active transversal PT bars, bothin the central section and in the lateral

LAS LLAMAS BRIDGE, SANTANDER, SPAIN

SPANNING URBAN GREEN

29CONNÆCT

prefabricated segments. For both ends, weused 64 mm diameter 460 N/mm2 stainlesssteel PT bars with fork end connections. Theinstallation was carried out such that thetension rod system is accessible for repair ormaintenance at any time. Struts were pinnedin the upper anchorage, to the steel platespreviously inserted into the concrete arch –each anchorage has four 25 mm diameter1,030 N/mm2 PT bars.

STRESSING OPERATIONSStruts were stressed symmetrically in respectto the axis of the arch. Two jacks wereplaced on the central bars of the lower plateanchorage and these were simultaneouslystressed to the first stage. The force exertedon the hangers was recorded by calibratedgauges on the jacks. An independent checkon the accuracy of these was provided bythe load cells and extensiometric stripswhich we had placed earlier.After all the central bars of the struts hadbeen stressed, we then post-tensioned thelongitudinal tendons and, lastly, the bars of thetransversal central box. Once this stage wascompleted, the installation of prefabricatedsegments began on both sides of the centralbox. Four 32 mm diameter 1,030 N/mm2 PT

bars were coupled to the central bars andstressed to complete the installation of theseelements.Once all prefabricated segments had beeninstalled, the upper slab – joining the centralbox to the prefabricated segments – wasconcreted in three stages to balance theintroduction of dead forces. Later theclearance between the lower strutanchorage and upper slab concrete boxwere filled with grout. Finally, all the strut bars were re-stresseduntil they reached their final force. All barswere protected against corrosion by a layerof cement grout injected into the ductsenclosing the bars.The bridge is required to play a leading role,both day and night. In daylight hours, itsgraceful figure is silhouetted against the Sports

Palace, in the east, or against the Picos deEuropa mountains, in the west – while, atnight time, its carefully designed lightingcreates a magical glow over Las Llamas park.No normal streetlights here – indirect lightinghas been arranged on the rails andstrategically placed spotlights illuminateselected braces and feet. The points of lightplaced at the bottom of the deck permit afuller appreciation of this structure whichstands just 16 m above the river bed. l

BRIDGES

TEAM & TECHNOLOGYOWNER Santander City Hall

MAIN CONTRACTOR Isolux Corsan S.A.

DESIGNER Arenas & Asociados

TECHNOLOGY BBR VT CONA CMI internalPT bar


30 CONNÆCT

The Nitra to Selenec sectionof the R1 Motorway is a 52km long extension of the

route between the towns of BanskaBystrica and Nitra, which is about100 km east of Bratislava, theSlovakian capital. NorbertBogensperger from Austrian BBRNetwork Member Vorspann-Technik explains that, to closeone of the last gaps – and withinthe first Slovakian Private PublicPartnership infrastructure project –a 1,165 m long bridge structurewas built.

The bridge arches above the southern outercircle of Nitra, a railway line, some roads andthe River Nitra. The structure consists of twosections – DC1 and DC2.

DC1: LAUNCHED MONOLITHIC BOXGIRDERDC1 is a cyclically launched monolithic boxgirder – consisting of two independentlybuilt bridges side-by-side supporting thetwo carriageways. A single deck is 12.65 mwide and 804 m long. The spans vary –depending on the terrain – between 40 mand 45 m and pier heights range from 7.1m to 10.9 m

DC2: PT CELL GIRDERThe superstructure of DC2, which crossesthe river, is a five-span post-tensioned cellgirder consisting of three cells and a deckwidth of about 26 m.

We used the BBR VT CONA CMB externalband post tensioning system, all designed as04 x 0406 which means four bands with fourstrands each. This system was also used inboth structures – for DC1, as well as DC2 –with lengths mainly between 151 m and 177 m. l

CLOSING THE GAPR1 MOTORWAY BRIDGE, NITRA, SLOVAKIA

TEAM & TECHNOLOGYOWNER GRANVIA Construction, s.r.o. (PPP)

MAIN CONTRACTOR A-Hid Epito Zrt.

DESIGNER DOPRAVAPROJECT, Bratislava

TECHNOLOGY BBR VT CONA CMB band

BBR NETWORK MEMBER Vorspann-TechnikGmbH (Austria)

31CONNÆCT

A1 MOTORWAY, UPPER SILESIA, POLAND

RECORD FORSILENT JOINTSIn the densely urbanized and industrialized region ofUpper Silesia, Poland, BBR Polska is responsible for the

delivery and installation of expansion joints on the 36.2 km long Maciejow to Pyrzowice section of the new A1motorway.The range of work includes production, delivery and installation ofsingle and modular expansion joints for the project. This is a highlycomplex construction project because it is taking place in a coalmining area. The effect of mining operations causes groundsettlement and this can often amount to as much several metersover the years. So, during the design phase, the potentially largemovements of the main structure had to be taken into account whenspecifying expansion joints.We are delivering 122 expansion joints, 86 of which are modularjoints with a total length of almost 2,000 m. The largest joints have apossible longitudinal movement range of +/-480 mm and +/-90 mm transversally. In addition, this was the first time expansionjoints with noise reduction features had been used in Poland. These rely on the installation of sinus plates on the top of the jointand installation of special soundproof mats. As cars cross over a joint,these elements then combine to make a significant reduction in theattendant noise levels. The joints were completed with extrareinforcement, provided by polymeric concrete. l

BRIDGES

TEAM & TECHNOLOGYOWNER General Directorate for National Roads and Motorways (GDDkiA),Katowice Division

MAIN CONTRACTORBudimex S.A. & Dragados S.A.

TECHNOLOGY Expansion joint

BBR NETWORK MEMBER BBR Polska Sp. z o.o. (Poland)

RIBNICA BRIDGE, PODGORICA, MONTENEGRO

High quality access routeThe 8 km long Podgorica Eastern Bypass is the most

expensive and demanding infrastructure projectrecently built in the capital city of Montenegro, recountsDamir Pavicic of Croatian BBR Network Member, BBRAdria.Construction of this project, to echo the words of Podgorica’sMayor, is significant – not only for the City of Podgorica, but forthe whole of Montenegro – because it provides an easy, highquality access route to the sea and port of Bar, as well asimportant commercial destinations and neighboring countries.Professor Mladen Ulicevic, the lead designer, describes RibnicaBridge as the biggest structure on Podgorica’s bypass. The bridgeconsists of four 3.5 m wide traffic lanes, a pedestrian lane andprotective lane. On the right, downstream side, the bridge is 9.61 m wide, whilst on the left side it is 10.67 m wide. A separate 290 m long structure was built for each carriageway.The bridge was designed as modern post-tensioned constructionwith nine spans of 30-35 m and 10 m high piers. It was post-tensioned using BBR VT CONA CMI 1206 and 1506 tendons. A total of 107 t of PT strand were used in the construction. The superstructure was built in five months using traditionalformwork and scaffolding. l

TEAM & TECHNOLOGYOWNERCity of Podgorica, Agency for Construction and Development d.o.o.

MAIN CONTRACTOR Celebic d.o.o.

DESIGNER prof. Mladen Ulicevic, CDS Project d.o.o.


BBR NETWORK MEMBER BBR Adria d.o.o. (Croatia)

32 CONNÆCT

To respond to emerging technologies andchanges in clinical practice andpopulation health, the New South Wales

Department of Health, in a partnership with theprivate sector, provided the funds for theredevelopment of the Royal North ShoreHospital which lies five kilometers to the northwest of Sydney’s Central Business District. SamFassaie of BBR Network Member StructuralSystems Limited shares some of the project’shighlights.

The project is the largest ever health Public PrivatePartnership (PPP) undertaken in New South Wales. The PPPhas enabled architects and planners to draw on the best ideasfrom around the world and deliver an expandable design thatcan grow and change in response to healthcare needs.The redevelopment project includes a new main hospitalbuilding (Acute Care Facility), a new Community HealthBuilding and the refurbishment of some existing buildings.When completed, the redeveloped Royal North ShoreHospital will offer :u 462 acute beds to complement the 124 beds providedwithin the already completed Douglas Building

u 40 acute mental health bedsu Additional chemotherapy and renal dialysis chairsu Enhanced diagnostic services and ambulatory care servicesu A total of 29 procedure and operating rooms.The Acute Care Facility is relatively low rise, with innovativecolor-coded internal spaces to help people navigate thehospital environment. The design maximizes local views, lightand space to create a welcoming, healing environment, whilethe compact footprint ensures that every department is withintwo minutes walk of the main lifts. It will include newcommercial and retail areas for the convenience of staff,patients and visitors. We were commissioned by the main contractor to providethe design and installation of post-tensioning to the AcuteCare Facility and the New Community Health Precinct. Ontop of the post-tensioning works, we were also awarded thecontact for the slipform construction of four stair and lift shaftsin the Acute Care Facility.

SPEEDY SLIPFORMDue to the tight program, the main contractor examineddifferent options for constructing the four sets of central coresthat would directly affect the speed of constructing the 10 levelsof the building. Slipform construction was the solution chosento achieve the program, due in part to its superior speed, as

Strongand healthy

A NEW HELIPAD ... NEEDED A SPECIALDESIGN BECAUSE OF THE LIMITED NUMBEROF COLUMNS, VERY LONG CANTILEVER – UPTO 7.5 M LONG – AND VARIABLE LOADING

“”

ROYAL NORTH SHORE HOSPITAL REDEVELOPMENT,SYDNEY, AUSTRALIA

33CONNÆCT

well as flexibility in design and operation.The slipform technique is a rapid andeconomical construction method that canachieve considerable cost savings whencompared with the cost of conventionalformwork. Each set of cores contained two to four liftshafts, plus fire escape stairs, which requireda specific design, as well as specialized

equipment and installation. The slipformelements were assembled off-site and thentransported to site for the final assembly. Theexistence of tower cranes within some ofthe lift cores demanded sophisticated steelframes to secure the yokes and panels intheir places. Special provision and designwere also in place for the numerousopenings within the walls. We were able torun two slipforms at the same time tomaximize the construction speed on site.

VIABLE ECONOMICAL SOLUTIONThe column layouts are generally with 10.8 m and 8.4 m spans – almost impossibleto design with conventional reinforcement.Consequently, the viable and economicalsolution to this arrangement was post-

tensioning of the beams and slabs for thenominated design loads.The design of the Acute Care Facility’s post-tensioned floors began in the second half of2009. All of the slabs from levels 2 to 10were designed and executed using the BBRCONA flat post-tensioning system. Level 2alone is 15,500 m2 and needed to bedesigned for a variety of loadings – includinga loading dock, MRI and other medicalequipment, the path for transportingequipment into place and many transfercolumns.As post-tensioned slabs are typically muchthinner than conventional slabs, detailedanalysis was carried out for vibration andnoise to ensure the multitude of sensitivemedical equipment – such as MRI or CTscanners – would function accurately.There were areas within the post- g

BUILDINGS

Facts & figuresu Suspended slabs – 106,000 m2

u Strand – over 625 km u Ducting – over 160 kmu Engineering drawings – over 1,400 issued

... THE VIABLE ANDECONOMICAL SOLUTION TOTHIS ARRANGEMENT WAS POST-TENSIONING OF THE BEAMSAND SLABS FOR THENOMINATED DESIGN LOADS.

“”

34 CONNÆCT

tensioned slabs where uncertaintyprevailed about the location of thepenetrations required for the services. As aresult, certain areas were noted on ourdrawings as ‘PT Exclusion Zones’ to provideflexibility for coring in future. These areaswere also marked up on the slabs duringconstruction.

NEW HELIPADA new helipad is also part of the AcuteCare Facility and needed a special designbecause of the limited number of columns,very long cantilever – up to 7.5 m long –and variable loading. Two differentengineering design programs, RAPT andRAM Concept, were used to ensure theresults were consistent and to verify design.Through our client, we liaised with theaviation authorities to ensure all possibleiterations of loadings applied on thisimportant structure were accounted for.The multitude of post-tensioning tendonsmade the centre of the helipad verycongested with a large amount of stress inthe concrete. As a result, dead ends of thetendons had to stagger within the depthand also across, so as to spread the

enormous stress in a larger section. Specialanalysis and detailing were carried out forthe amount of reinforcement neededwithin that zone and also a higher grade ofconcrete – 50 MPa cylinder strength – wasdetermined for this slab. The helipad is in aprominent position which makes it visiblefrom many angles, even from SydneyHarbour Bridge – making the helipad anew monument for Sydney.We also designed and installed post-tensioning for the new Community HealthCentre as part of the project. More than60 t of CONA flat post-tensioning wasinstalled in around 12,000 m2 of slabs.Construction now completed, this buildingprovides a range of facilities to supportcommunity health services. l

REHEARSAL STAGE, VIENNA OPERA HOUSE, AUSTRIA

Room for rehearsal

Norbert Bogensperger, of BBRNetwork Member Vorspann-

Technik in Austria reports on aproject for the world famousOpera House which is located onthe Ringstrasse in the heart ofVienna. It was built between 1861and 1869, in the Neo-Renaissancestyle typical of other famousViennese buildings.

The problem with this historic building is thatit offers too little storage space for sceneryand just a small rehearsal stage, less than halfof the size of the real stage. Thus, thedecision was made to add on a full-scale 800 m2 rehearsal stage to the existingscenery depot, a few kilometers away in theArsenal area.This allows even choral and mass scenes tobe rehearsed using the original stage scenerywhich just has to be rolled a few meters outof the depot.Architecturally, the new building appears tobe a levitating cube. It is grounded just byfour piers and the whole ground floor – atmore than four meters high – is an openarea for truck loading and storage.Therefore, the 70 cm thick first floor slabwas constructed with a special concrete anda tight cross-layering of BBR VT CONACMM 0406 bands to handle these enormousspans of more than 25 m. l

TEAM & TECHNOLOGYOWNER ART for ART Theaterservice GmbH

MAIN CONTRACTORBilfinger Berger Baugesellschaft mbH

DESIGNER nowy-zorn ZT GmbH

TECHNOLOGYBBR VT CONA CMM monostrand


TEAM & TECHNOLOGYOWNER InfraShore Pty Ltd

MAIN CONTRACTOR Thiess Pty Ltd

PT SLABS & SLIPFORM DESIGNERStructural Systems Limited (Australia)

TECHNOLOGY BBR CONA flatSlipform

BBR NETWORK MEMBER`Structural Systems Limited (Australia)

35CONNÆCT

The Arena Center covers an area of175,000 m2 which accommodates morethan 220 different shops, a bowling alleyand a multiplex cinema with an IMAXtheatre. There are 3,500 parking spaces,most of which are housed in one under-ground level. In an eight month period,we executed 72,000 m2 of post-tension-ed slabs using the BBR VT CONA CMM106 unbonded system, with 150 mm2

1860 MPa strand. Some 420 t of steelprestressing strand was consumed. The PT slabs were designed using theshallow beam concept. The generalcolumn layout is 8 m by 16 m, exceptwhere supermarket design specificationsdemanded a 16 m by 16 m grid. Thebeam depth is 50 cm to 55 cm, with slabthicknesses of 20 cm to 25 cm, depend-ing on the load requirement. The excep-tion was a 16 m by 16 m area with a 60 cm beam and 30 cm slab. Tendons arebanded only in beams in the 16 m direc-tion – elsewhere they are distributed.Slender PT slabs enabled optimal spaceutilization and we managed to insert oneadditional slab in parking sections B andC. In section A, an 8 m wide PT strip wasleft in the middle to be cast and stressedat the end – because of its 144 m length.Section D is geometrically more complex,with cantilevering galleries and pedestrianbridges.

Inside prefabricated sections, post-tensioning was also used in two places –due to geometrical complexity and bigspans. One application involved a 6.9 mlong cantilever used as a restaurantterrace right over the Arena's mainentrance. The slab incorporating thecantilever was produced on a 16 by sixmeter grid, so that the cantilever waslonger than the adjacent slab span. Thisdemanding structure was resolved with ashallow beam grid 60 cm deep and a 20 cm slab. The second complex areawas a side entrance in Section 4 with acurved beam spanning 18.5 m and a 9.5 m by 4.5 m light well opening.We found unbonded post-tensioningtechnology to be of great advantage –due to speed and practicality ofexecution, larger casting segments andfaster working progress even in thewinter months. l

BUILDINGS

This ultra-modern fourthgeneration shopping andentertainment center is

located beside the Zagreb Arena in the south west of the city. Theinternational TriGranit consortiuminvested €350 million in thedevelopment of the Arena Centerwhich now employs around 3,000people. Construction of the centertook about 18 months, reports DamirPavicic of BBR Adria, the NetworkMember in Croatia.

Creatingspace forretail andleisure

TEAM & TECHNOLOGYOWNER TriGranit Laniste d.o.o. Zagreb

MAIN CONTRACTOR MI GRUPA (Mucic& Co, Medjimurje graditeljstvo & Tromont)

DESIGNER Berislav Medic, UPI-2M, ZagrebMiljenko Kovac & Predrag Presecki, K.A. biro,Cakovec


BBR NETWORK MEMBER BBR Adria d.o.o. (Croatia)

ARENA CENTER, ZAGREB, CROATIA

36 CONNÆCT

We present details of three different slabprojects here – one constructed by BBRConstruction Systems in Malaysia, another byBBR Contech in New Zealand and a third byBBR Polska – which demonstrate not onlytechnical excellence, but also the enhancedfitness-for-purpose of solutions based aroundBBR technology and know-how.

ALTERNATIVE GATEWAY TOMALAYSIAMika Jakau of Malaysia-based BBRConstruction Systems reports how post-tensioned flat slab methodology is enhancingconstruction progress and providingeconomic savings to the construction of carpark blocks at the new Low Cost CarriageTerminal (LCCT) next to Kuala LumpurInternational Airport in Sepang. There aretwo seven storey car park blocks, with a totalcar parking area of 140,000 m2 and withcolumn grids mainly at 8.4 m by 8.4 m – andsome areas 9 m by 9 m. Each 8.4 m and 9 mbay is divided by two intermediate beams,resulting in three slabs per bay.

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To reduce formwork and labor costs whilereducing program time, we proposed apost-tensioned flat slab approach, utilizingBBR CONA flat tendons. Each 208 m by 52 m floor of each block is divided into tenconstruction zones to suit the client’sconstruction sequence. By changing thestructure to flat slab, the client is able touse his existing table formwork, which gavehim the competitive edge in securing thisproject.

ELEVATING PERFORMANCEHaving chosen a cast in-situ post-tensionedconcrete structure and experienced itssignificant construction and delivery benefitson our earlier Sylvia Park project together,main contractor Brookfield Multiplex is againinvolved with a car park. This time it is for asix-storey structure to provide 1,200 spacesfor Auckland’s North Shore Hospital. BBRContech Project Manager Hugo Jacksonoutlines the details.Comprising a total floor area of 27,700 m2

– around 4,600 m2 per storey – the floorcontains approximately 170 t of post-tensioning. The floor structure consists of 150 mm thick concrete slabs with wide bandbeams in one direction and seismic resistingframe in the other. Each level is constructed asthree pours on relocatable forms and a storeyis completed on average every two weeks.Our post-tensioned flooring solution offers anumber of benefits for car park structureslike these. It is economical and relativelyquick to install, and it saves material costsand construction time, while also enablingthe client to reduce the distance betweeneach parking level. It delivers a great surfacetoo, providing users with a smooth drivingand parking experience.

PYRZOWICE TECHNICAL HANGARParking experiences of a different scalefaced the BBR Network in the constructionof the first ever post-tensioned slab onground to be used in Poland for parkingaircraft. Karolina Haponik of BBR Polskaexplains that the 6,400 m2 slab, at the

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The BBR Network’s expertise has delivered innovative and market-leading floor solutions for specialist applications. By adopting apost-tensioned approach, our customers can be certain of both

improved construction programs and higher performance.

Flooring the competitionPARKING STRUCTURES IN MALAYSIA, POLAND AND NEW ZEALAND

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37CONNÆCT

BUILDINGS

TEAM & TECHNOLOGYOWNER Goodman Property Trust

MAIN CONTRACTORMacrennie Commercial Construction

DESIGNER MSC Consulting

FLOORING CONTRACTOR Conslab Ltd

TECHNOLOGY BBR CONA flat


K-MART DISTRIBUTION WAREHOUSE, AUCKLAND, NEW ZEALAND

Recognizing concrete excellence

Technical Hangar at Katowice Airport inPyrzowice, was designed as a monolithic plate ofpost-tensioned concrete, divided into two mirror-image sections and separated by a 10 mmexpansion joint.Slab thickness varies – according to anticipatedload factors – from 200 mm in the aisle, 250 mmon the outside apron, to 360 mm for the apronitself. Each section is divided into four furthersections which were concreted in continuouspours, then stressed in two stages.Transverse tendons from sections 2, 3 and 4 wereanchored in the main section, so that all sections

were stressed together. The main360 mm slab was designed totransfer aircraft loads – concretinghere lasted for 16 hours.We used BBR VT CONA CMM0106 tendons with strands of 15.7 mm nominal diameter, 150 mm2 cross-section and atensile strength 1860 MPa. Allstrands were prefabricated on theprefabrication line within our ownproduction plant and delivered onsite in ready-to-install condition.l

TEAMS & TECHNOLOGIES

LOW COST CARRIAGE TERMINALOWNER Malaysia Airports Holdings Berhad

MAIN CONTRACTOR WCT Construction Sdn Bhd

CLIENT TKM Resources Sdn Bhd

DESIGNER BBR Construction Systems (M) Sdn Bhd


BBR NETWORK MEMBERBBR Construction Systems (M) Sdn Bhd (Malaysia)

NORTH SHORE HOSPITALOWNER Waitemata District Health Board

MAIN CONTRACTOR Brookfield Multiplex

DESIGNER MSC Consulting



PYRZOWICE TECHNICAL HANGAROWNER Gornoslaskie Towarzystwo Lotnicze S.A.

MAIN CONTRACTOR Polimex – Mostostal

DESIGNER P.S. Budoprojekt (PT slab on ground by SDS Sp. z o.o.)

TECHNOLOGY BBR VT CONA CMM monostrand


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It is not oftenthat concrete floors win prizes,but a project with which BBR

Contech was associated hasbeen recognised as an

outstanding achievement in concreteconstruction and has earned top honors in theNew Zealand Concrete Society’s ConcreteAwards 2011. BBR Contech Project Manager,Terry Palmer, describes this latest achievement.Concrete floor specialist Conslab was presentedwith both the Technology Award and thesupreme Concrete Award for its construction oftwo floor slabs for a K-Mart distributionwarehouse in South Auckland. One floor –smooth, flat, highly polished and post-tensioned –is inside the warehouse, and the other – a jointedsteel fiber reinforced slab finished with a skid-resistant, free-draining surface – forms a truckloading and unloading area outside. Conslabcalled on us to design, supply and install the post-tensioning for the interior slab. Covering almost 13,000 m2 with a thickness of 160 mm. It wascreated in four pours and stressed into one largeslab with no free movement joints

By meeting the rigorous FM2criteria of theEuropean racking codeEN 15620, it enables the owner toclose up the spacing between racksto ‘Very Narrow Aisle’ (VNA)racking, with minimal grindingnecessary to bring the slab to adefined movement specification.According to the judges, theproject illustrated “a verycomprehensive understanding ofwarehouse and hard-standing slabperformance and construction” and“the exceptional level of concretedesign and construction excellencethat the Concrete Society Awarddemands.”The surface flatness ensures highproductivity for the forklifts – a keyfactor in logistics warehousing. Thefinished surface has high lightreflectivity – a quality delivered bythe floor’s light color and high-gloss

finish which, together with the use of clearroofing, has reduced the warehouse lightingrequirements. In addition, the 40 MPa concrete – highly burnished and well cured – has excellentabrasion resistance, ensuring a floor that will lastfor many years to come. l

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38 CONNÆCT

The project involves the A$110 millionredevelopment of the Dee Why Hotel andcontains car parking, retail and commercialareas – together with six residential towers,rising three to eight storeys above alandscaped podium. We were contracted bySouthern Cross Constructions to design andinstall the post-tensioning for the project.

DIFFICULTIES & CHALLENGESThe project presented a number of uniquechallenges, especially relating to thegroundwork and basement constructionbelow Dee Why’s shallow water course. Thelargest piling rigs in Australia were used toinstall the 32 m sheet pile walls around theperimeter and the deep excavation now

hosts three basement car park levels andtwo levels of retail stores. A further challenge was that the structurehad large floor plates with a considerablenumber of reinforced cast in-situ concretecores positioned in several locations acrossthe floor area. These rigid elements createdrestraint issues. Added to this, the lowerlevels which include the basement and retaillevels were restrained by the sheet pileretaining walls. To deal with the restraintissue, both temporary and permanentmovement joints were introduced to isolatefrom the reinforced concrete cores. Delayedconventionally reinforced pour strips wereintroduced around the perimeter to isolatefrom the sheet pile wall which also providedaccess for stressing and eliminated the needto use surface stressing pans.

PT SOLUTIONPost-tensioning was used throughout thesuspended floors which are cast-in-situconcrete, incorporating more than 360 t ofBBR CONA flat slab post-tensioning. The design of the suspended floors made useof a number of slab systems which includeone-way slabs supported by band beams,two-way flat plate and two-way slabs withdrop panels. The basement car park slabswere generally one-way slabs supported byband beams, the retail levels were flat plateswith drop panels to allow for the passage of

The Dee Why Grand is a new mixed-use development situatedamidst Sydney’s northern beaches. The development has formedpart of Warringah Council’s Dee Why Environmental Plan to

rejuvenate the local area, bringing new energy and affluence to theNorthern Beaches. George Marinos, of Australian BBR Network MemberStructural Systems Limited, gives an overview of the project.

Grandresult

DEE WHY GRAND, SYDNEY, AUSTRALIA

39CONNÆCT

services without restricting head height andthe residential floors were typically flat platedue to the head height constraint – 2.7 mceilings. These slab systems were chosenwith the aim of providing the most efficientand low-cost solution to the client. This wasachieved by the attendant reduction inmaterials and increase in the speed ofconstruction without compromising thestructural integrity, quality or architecturalrequirements of the structure.The Level 1 podium slab is a heavy transferslab with complex concrete profiles due tothe combination of varying slab thicknesses,deep folds and steps, large spanning beams –some in excess of 16 m – to cater for thelarge column-free space below required forthe loading dock, diagonal beams and themagnitude and positioning of the transfercolumns. Input from the design team wascritical to arriving at a practical solution. Theslab depths and beam dimensions werereviewed – in discussion with the consultingengineers, the architect and services con-sultants – and this led to significant changes inthe concrete profiles. Due to the geometricconfinements of some slabs and beams, weused 12.7 mm and 15.2 mm diameter strand.

In addition, the dimensions of various transferbeams were restricted in depth and widthand could not be increased due to headheight limitations – widths could only beincreased to a certain extent. This createdissues with practicality and great difficulties inphysically installing the considerable quantityof post-tensioning strand required to controldeflections. Therefore, the design of thebeams used a combination of BBR CONAflat slab post-tensioning and BBR VT CONACMI which reduced congestion and improvedthe construction efficiency of the floor.With the use of post-tensioning, thoughtfuldesign and efficient construction, the projectrecovered from being well behind its targetconstruction program – when we began thesuspended structure – to finishing ahead ofschedule on its completion. l

MAGISTRATES’ COURTS, ESSEX,ENGLAND

Reducing legal costs

Post-tensioning which was designed andinstalled by BBR Network MemberStructural Systems UK has beenused to reduce the environmentalimpact on two new Magistrates’ Courtbuildings currently being developed inColchester and Chelmsford, Essex.Richard Gaskill takes up the story.Both buildings were designed to sit onexisting car parks and have a similarlayout. During the initial design reviewworkshops, some 50 potential designchanges were identified with 11 ideasflagged up for further discussion and,finally, this number was distilled down tofour which were analyzed in detail. Post-tensioning, along with retention ofexcavated material, pre-engineered stairsand CFA replacement piles reduced theoverall cost of the structures. TheColchester structure had slab depthsvarying from 200 mm to 400 mm,whereas the one in Chelmsford variedfrom 200 mm to 500 mm thick. TheMagistrates’ Court scheme was procuredthrough a Private Finance Initiative (PFI)scheme by the County Council, to securethe new courts as part of a countywidecourt strategy. Her Majesty’s CourtService is expected to pay £30 millionfor the Colchester Magistrates’ CourtComplex. The Court is due to hold itsfirst case in summer 2012.The Courthouse is designed to theHMCS Design Guide 2007 and is set toachieve BREEAM excellent and otherspecific targets from the UK GovernmentFramework for Sustainable Development.

BUILDINGS

TEAM & TECHNOLOGYOWNER Her Majesty’s Court Service

MAIN CONTRACTOR Galliford Try


BBR NETWORK MEMBERStructural Systems (UK) Ltd

Local insight:Dee Why

Today, Dee Why is undergoingconsiderable urban regeneration

and proving popular with youngprofessionals, perhaps attracted by aneasy commute into the Sydney CBD. The first written reference to the townappears in the field book of Irish-Australian explorer and surveyorJames Meehan: “Wednesday, 27th

Sept, 1815 Dy Beach – Marked aHoney Suckle Tree near the Beach.”Explanations for his description rangefrom the DY simply being a code thathe used on maps, or that it originallycame from the local Aboriginallanguage or was derived fromcalculus and refers to the shape of thecurve of the beach as seen on a map.From 1940, the town was known as‘Deewhy’ and it was only in the 1950sthat it took the present form – DeeWhy.Since construction of the new civiccentre in the early 1970s, the townhas housed the administrativeheadquarters of Warringah Council,the local authority.

TEAM & TECHNOLOGYOWNER Dee Why Developments

MAIN CONTRACTOR Thiess Pty Ltd

DESIGNER Structural Systems Limited (Australia)

TECHNOLOGY BBR CONA flat BBR VT CONA CMI internal


… A COMBINATION OF BBRCONA FLAT SLAB POST-TENSIONING AND BBR VTCONA CMI ... REDUCEDCONGESTION AND IMPROVEDTHE CONSTRUCTIONEFFICIENCY OF THE FLOOR.

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40 CONNÆCT

The new ADNOC headquarters occupiesone of the most prestigious addresses in theUnited Arab Emirates and, indeed, in thewhole of the Middle East. It standsimmediately opposite the luxurious EmiratesPalace Hotel and the new presidential palacewhich is currently under construction. The75-storey ADNOC HQ building will achieveeither Gold or Platinum LEED Certificationupon completion, as the constructionsystems and methodologies employed willminimize the building’s impact on theenvironment. Apart from office space, thetower will include a Corniche Club, theSupreme Petroleum Council and CrisisManagement Centre, Heritage Museum andother supporting facilities.

STRUCTUREThe concept of the structure is veryminimalistic, taking into account that thefootprint of a typical level is approximately2,450 m2. Post-tensioned floors aresupported on the west, south and east by

large cores and only six perimeter columns atnine meter spacing on the north side.The south core reduces in size towards thetop of the tower. Cores to the west and eastdo not diminish in overall size, but thethickness of their walls decreases with height.

The maximum thickness of walls in the coresis a substantial 1.2 m at the lower levels.Columns were designed as concrete-filledsteel tubes (CFT) of a 1.5 m maximum dia-meter at lower floors and a steel tube thick-ness of 90 mm. The column diameter reducestowards the top of the building. In addition tothese vertical elements, there are three

service levels with outrigger walls – spanningbetween columns – and cores to limit thehorizontal movement of the structure.

PT SYSTEMSA post-tensioned band beam option waschosen for the typical levels, thus providingthe most economic and minimum depthoption for the client – with the majority ofbeams spanning a significant 16.8 m in onedirection between the main core and theCFT columns, from where the bandscantilever six meters to the slab edge. Theband beam size for the typical levels is 3,000 mm wide and 550 mm deep. The 200 mm deep reinforced concrete slabswhich span between these band beams weredesigned and detailed by Structural Systems.Service levels were designed as flat slabs 450 mm to 500 mm deep – the thicknessdepending on the loading and locations – and the consultant required additional pre-compression to be provided below andabove every outrigger wall to improve thelateral stability of the structure.

DESIGN CHALLENGESSpecial steel connection details between thepost-tensioned banded beams and everyCFT column required considerable additionalreinforcement to meet the engineer’s require-ments. This detail did not give us a lot ofspace to run the three ducts with five 15.2 mm strands on either side of thecolumns. Another of the numerouschallenges was to cater for the extremecantilevers which were typically six meters,but extended in certain locations to up to 10.8 m in length. We were responsible forensuring that perimeter deflections werecontrolled and that the very sensitive 4.4 mtall glass-faced panels would not be damagedby floor slab deflection. Numerous meetingswere held between the designer, contractorand ourselves to make sure that the designand details were integrated and, mostimportantly, that the details shown on thedrawings were actually buildable on site.

INSTALLATION CHALLENGESProbably the biggest challenge, from an on-site point-of-view, was to satisfy theengineer’s requirement for a minimum of50% of the tendons to be fully anchored inthe core walls. This was achieved in thelower floors by installing dead end ‘onions’inside the walls, but the heavily congestedwall reinforcement made this a difficult task.As works progressed to the upper floors,the main contractor wanted to construct allcores in advance of the floors. This then

The new corporate headquarters complex for Abu Dhabi NationalOil Company (ADNOC) is being built on the Abu Dhabi Citycorniche. This magnificent 342 m high tower with excellent views

of the Arabian Sea will be one of the tallest towers in Abu Dhabi. RolandZachar, Design Manager and Warwick Ironmonger, General Manager,both from Structural Systems Middle East, the BBR Network Memberbased in the United Arab Emirates, report on the challenges overcomewhilst designing and building this iconic building.

Stressing for new icon

PROBABLY THE BIGGESTCHALLENGE ... WAS TO SATISFYTHE ENGINEER’S REQUIREMENTFOR A MINIMUM OF 50% OFTHE TENDONS TO BE FULLYANCHORED IN THE COREWALLS.

ADNOC HQ, ABU DHABI, UNITED ARAB EMIRATES

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Fostering creativity

41CONNÆCT

necessitated the installation of live, ratherthan dead, anchorages with ‘dummytendons’ in the walls. Stressing of thesetendons had to be done from inside thecore. With access to the live ends availableonly from the top of the core walls, our siteteam had to go down two levels inside thecore to perform stressing operations. Withoutside temperatures often exceeding 45 ºC, limited ventilation inside the corewalls and the extreme humidityencountered, we ultimately built this iconwith sweat and determination! l

The building, which is a showcase for eco-friendliness and flexibility, consists of twoparts – the Backdrop and Blank Canvas. TheBackdrop is a podium containing a concerthall, drama theatre, black box theatre andseveral small performing spaces. Meanwhile,Blank Canvas provides the school areawhere the curriculum fosters greater clarityof insight, critical evaluation and creativity.Post-tensioning has been used to providegenerously proportioned classrooms withperforming space by increasing theheadroom and allows longer spans betweencolumns. In addition, the classrooms aredesigned in nine meter square modules withmovable end walls which allow for futurechanges in use.This project is a composite structure, usingboth steel and concrete. The columns aremade of steel and encased in concrete forfire protection. During construction, therewere difficulties in connecting the columnsand beams with PT tendons and we resolved

this by adopting an unconventional method.Firstly, reinforcement bars were welded tothe steel column. Part of the beam was a‘box-out’ at the stressing anchors. Thereinforcement bars of the beam were bentup temporarily to allow access for thestressing jacks. After the tendons had beenstressed, the bars were bent back intoposition and the box-out was concreted.The formwork was removed only after theconcrete had gained sufficient strength. l

BUILDINGS

TEAM & TECHNOLOGYOWNER Abu Dhabi National Oil Company

MAIN CONTRACTOR Six Construct Co. Ltd


BBR NETWORK MEMBER Structural SystemsMiddle East LLC (United Arab Emirates)

Situated in The Arts & Heritage district of Singapore, the School of the Artsis the first independent pre-tertiary Arts school to nurture youths who arepassionate about and committed to the Arts in a multi-cultural society. It

also aims to nurture the next generation of artists and creative professionals,reports Kew Kim Mei of BBR Construction Systems in Singapore.

TEAM & TECHNOLOGYOWNER Ministry of Information,Communications and the Arts

MAIN CONTRACTORTiong Aik Construction Pte LtdSTRUCTURAL CONSULTANTWorley Parsons Ltd

TECHNOLOGY BBR CONA flatBBR CONA internal

BBR NETWORK MEMBERBBR Construction Systems Pte Ltd (Singapore)

SCHOOL OF THE ARTS, SINGAPORE (SOTA)

42 CONNÆCT

BUSINESS GARDEN WARSAWIn Warsaw, we were commissioned toprovide PT services for the construction oftwo office buildings for the Business GardenWarsaw development near the internationalairport – the developer is planning to extendthis office complex later with another fivebuildings.The first building (B1) has a total servicearea of around 13,000 m2 while the secondbuilding (B2) is around 17,000 m2 – bothblocks are seven storeys high and have twounderground parking levels for 260 and 265cars respectively. All slabs are executed as PT slabs – in each building we executed ninepost-tensioned slabs which amounted to atotal of 51,500 m2 across the two buildings.Building B1 is very irregular shape with levels0 and +1 in one block, above which it dividesinto three towers. Tower A is three storeyshigh with floors typically of 450 m2, Tower B issix storeys high with floors typically of 640 m2

and in the six storey hotel tower typical floorsare 1200 m2, divided into two pours – only afew slabs are similar. Meanwhile, Building B2 isa more regular shape of three linked trianglesand all slabs above ground level are similar. PT slab solutions had already been chosen atthe preliminary design stage, however, thedeveloper allowed some alternatives. Forexample, evaluation was made of usingprefabricated concrete elements, however, in

1 the end, our PT solution turned out to bearound 15% cheaper.Building B1 will house a hotel, some publicservices, restaurants and office area andBuilding B2 will contain offices. The complexity of the building shape makesconstruction equally complex. Slab spans varyfrom seven to 11.5 m, often with a five metercantilever – the spans are very irregular. Inbuilding B1, slab thickness varies from 200 mmin the underground parking to 350 mm in thecantilever section of two towers. The RC rateis between 13 and 17 kg/m2. In building B2the typical floor has shape of three trianglesjoined together. Typical floors are 2600 m2,with slab thicknesses of 250 mm and 300 mm– here the RC rate varies between 15 kg/m2

in the underground parking and 10 kg/m2 fora typical floor – the latter is divided into threepours linked with expansion joints. All slabsare designed with C30/37 concrete. We used BBR VT CONA CMM 0106tendons made of 15.7 mm nominal diameterstrands with a 150 mm2 cross-section andtensile strength of 1860 MPa. In total, we used260 t of prestressing steel.

BRAMA PORTOWA I & II,SZCZECINMeanwhile, in Szczecin, our site manager,Bartosz Chmielewski, has been managing theBrama Portowa I and II development which

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comprises two buildings located in the veryheart of Szczecin city centre. Both buildingsare being performed with PT slabs using theunbonded BBR VT CONA CMM 0106system and in total, we used 50 t ofprestressing steel. The first structure is known as ‘Grzybek’(mushroom) and comprises 4,000 m2 ofoffice space, 580 m2 of service area and asingle-floor underground car park. In theabove ground levels, we are using 200 mmthick post-tensioned slabs – each slab covers900 m2.The second building – named ‘Poczta’ (post-office) – consists of 6,800 m2 of office spaceand a 1,400 m2 service area, including a carpark. The slabs for this building wereconstructed by making two pours for eachof the seven PT floors – each pour consistedof around 650 m2 of concrete.The buildings were originally designed withtraditional reinforced cast in-situ concrete.Slabs are supported by concrete columnsspaced about every eight meters, cores withstaircases and lifts, plus external walls. In thetender stage design, slabs were 250 mm thickand RC consumption was about 30 kg/m2.We proposed and delivered a post-tensioned slab solution which allowed theslab thickness to be reduced to 200 mm andRC rate to 12.5 kg/m2. With our PT solution,the general contractor saved around €5 persquare meter on slab construction.BBR Polska’s scope of work on both theWarsaw and Szczecin projects covereddelivery of alternative design for PT slabs,delivery, installation and stressing of tendons,plus delivery and installation of anchoragezone reinforcement. l

With the support of its dedicated post-tensioned slab technologydepartment, managed by Bartosz Lukijaniuk, BBR Polska hasbeen rather busy lately with two prestigious office projects –

one in Warsaw, the other in Szczecin. Their work proves that quality andeconomy can indeed go hand-in-hand.

TEAM & TECHNOLOGYCLIENT SwedeCenter

MAIN CONTRACTOR Hochtief Polska

DESIGNER Arcade PolskaPT slabs by SDS Sp. z o.o.



Driving quality and economy

OFFICE BUILDINGS, WARSAW & SZCZECIN,

POLAND

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43CONNÆCT

PLAZA 33, PETALING JAYA, MALAYSIA

Taking the loadAtwo stage casting with three stage stressing, was

designed as an engineering solution to handle theheavy casting weight of a transfer beam – thereby

preventing overloading of floors below – while reducingpropping costs. Mohd Yusri of BBR Construction SystemsMalaysia, describes the project.Plaza 33 is a Grade-A office building located in Section 13, Petaling Jayaand consists of two office towers of 16 and 25 storeys and a podium. The beam has a single span of 24.3 m supporting two columns carry-ing loads from 20 storeys. As the columns are spaced at eight meters,harped tendons with horizontal flat profiles between the columns aredesigned to provide an uplifting force to balance the gravity loads.The beam was first cast to a height of 1.7 m, with four fully-embeddedBBR CONA 1905 tendons. The props and backprops were designedto carry only 1.7 m of concrete, rather than the full height. Withoutthe PT solution, the construction loads transferred down to groundlevel would have exceeded the capacity of the constructed floors.Upon achieving a transfer strength of 30 N/mm2, the tendons werestressed to 75% UTS. The props and the 1.7 m deep beam, could nowsupport the casting load from the second pour for the remaining 3.3 mheight. After second stage stressing of another eight CONA 1905tendons, the props were removed. Stage 3 stressing was carried out forthe remaining six CONA 1905 tendons after construction of Level 7. The tendons could only be stressed from one side and to avoidobstruction to column rebar, the 18 anchorages were placed in fivelayers within the narrow 1.5 m wide beam. The final precompressionapplied to the beam was 3.5 MPa.Horizontal shear resistance between the two cast concrete layers wasprovided by vertical shear links. To ensure that the two cast layersacted monolithically during the second and third stage stressing, theprestress tendons were profiled to angle sharply across the horizontalconstruction joint by taking advantage of the harped tendon profiles. By employing prestressing technology and incorporating ourconstruction methodology in the prestressed beam design, the clienthas reaped the key rewards of savings in props, backprops costs – andprevented overloading the constructed floors below. l

ASIA SQUARE, MARINA BAY, SINGAPORE

Record cycles for high rise

Atwin tower mixed-use development – AsiaSquare – is rising in Singapore’s Marina BayBusiness and Financial Centre. It comprises

two million square feet of premium office space,60,000 ft2 of retail space, a 305-room five star luxuryhotel and a 100,000 ft2 fully sheltered and landscap-ed plaza. Lim Suan Suan and Yeo Swee Choo of BBRConstruction Systems, the BBR Network Memberin Singapore, outline their work in supplying, in-stalling and stressing works for the post-tensioningrequired in the construction of the two towers.Each tower provides a highly efficient, column-free floor plateconsisting of post-tensioned beams and RC slabs, supported byexternal columns and core walls. Deep haunches were providedwhere there are moment connections to the columns. Clashesbetween the tendons and reinforcements were studied andresolved long before construction commenced. We are proud to be able to say that, using a climbing formworksystem and working a 24-hour shift pattern, we are achieving a 7-day cycle for each pour – currently the local record for thefastest pour cycle. Post-tensioning systems not only cut down thecost of construction and self-weight of the building, overall it hasalso saved lots of time! l

BUILDINGS

TEAM & TECHNOLOGYOWNER Plaza 33 Sdn Bhd

MAIN CONTRACTOR Siab (M) Sdn Bhd

BUILDING DESIGNER/CONTRACTORBBR Construction Systems (M) Sdn Bhd



TEAM & TECHNOLOGYOWNER MGPA

MAIN CONTRACTOR Hyundai Engineering & Construction

STRUCTURAL CONSULTANT Meinhardt (S) Pte Ltd

TECHNOLOGY BBR CONA flatClimbing formwork

BBR NETWORK MEMBER BBR Construction Systems Pte Ltd (Singapore)

44 CONNÆCT

ExCeL London is an international events andconference centre, located in the RoyalDocks, which hosts a variety of events fromhigh profile exhibitions and conferences tointernational association meetings, awardceremonies and sporting events. In 2012, thevenue will host seven Olympic and fiveParalympic events.This second phase of development was afurther massive investment focused onproviding superior world class event facilitiesin London, as well giving added support tothe capital’s ambition to host an everincreasing number of high profile domesticand international shows. This internationalevents venue – now valued at around £300million in total – is the largest and mostversatile space in London.

In addition to the vast halls totaling 65,000 m2, there are five on-site hotelscatering for budget and luxury clients, whichprovide 1,500 rooms, plus over 90 fullyserviced apartments, 45 meeting rooms and3,700 on-site parking spaces.We teamed up with concrete constructionspecialist P.C. Harrington Contractors, whohad commenced a 47-week contract whichincluded the groundworks, drainage, pile capsand structural concrete for construction ofthe new North Hall and lorry way, as well asthe South Hall, lorry way and ramp.The scheme was designed by maincontractor Sir Robert McAlpine’s in housedesign team who indicated a PT density of30 kg/m3 for North and South Lorry waysand 25 kg/m3 for both the North and South

Hall. As part of their specification, they hadindicated that all strands should be 15.7 mmseven wire super-grade with a minimumbreaking load of 279 kN.Concrete strength was specified as aminimum of 40 MPa and the designaccommodated a one hour fire ratingrequirement. Each hall was separated intopours – with the North Hall having 10 andthe South Hall 12. The lorry ways were splitinto a further three and four poursrespectively. The slab was nominally 240 mm thick, with 475 mm deep beams – which covered approximately 65% of thescheme – at centers ranging from 7.8 m to10.5 m and a 600 mm deep beam at oneend. Pours 3, 6, 9 and 12 were 270 mm thick on the North Hall and 300 mm thick on the South Hall, with all ofthese areas being adjacent to the lorryways. The area of the halls and lorry waystogether totaled 27,689 m2.During our 16 weeks on site, we installedour CONA flat 206, 306 and 406 bondedpost-tensioning systems. Internal pans, where

International showcaseEXCEL, LONDON, UK

ExCeL London represents a £150 million investment in theexhibitions industry. The recent second phase of development haspushed ExCel London to around 100,000 m2 of flexible flat floor

exhibition and conference space. Richard Gaskill of Structural Systems– the BBR Network Member in the UK – describes this huge development.

TEAM & TECHNOLOGYOWNER ExCeL London

MAIN CONTRACTOR Sir Robert McAlpine



45CONNÆCT

required, were installed along each side adjacent to the lorry way toallow post-tensioning to take place.The project has provided much-needed additional exhibition andconference space, as well as a 5,000 seat semi-permanent auditoriumat this venue. One of the more unusual features of the constructionprocess was that – after completion of the column pile caps – themain contractor erected the steel frame and roof, while thesuspended post-tensioned floor slabs for the exhibition halls andlorry access way were constructed afterwards. Among the challengesduring our construction period was the need to maintain access formaritime exhibits during the London International Boat Show! l

Bahrain Investment Wharf (BIW) is a joint venturebetween the Bahrain Government and Al Khaleej

Development Company (Tameer). Roland Zachar, DesignManager for BBR Network Member NASA StructuralSystems LLC, reports how they have helped to developthe wharf by post-tensioning the floor slabs of the newfive star BIW Hotel. The master plan of the US$2 billion BIW project is divided intofour major sectors – an industrial park, business park, residentialand service areas – totaling 1.25 million square meters ofrentable area. BIW is strategically located – near to Bahrain’sInternational Airport, the Seaport, the highway leading to thecauseway linking Bahrain and Saudi Arabia, as well as the newlyproposed causeway between Bahrain and Qatar – for ease ofimport and export of goods.Given the significant overall length of the project, each level of thehotel was divided into three pours by the inclusion of expansionjoints. All 13 levels above the ground were designed as post-tensioned flat slabs using the BBR CONA flat system with 305 and505 anchorage sizes. The lower, more heavily loaded levels,consisted of 220 mm deep post-tensioned flat slabs, whereas slabdepths of only 200 mm were required for the upper levels.The majority of projects in the Middle East over recent years havebeen carried out at a much faster pace than is typically experiencedin Europe. The period between signing the contract, finalizing thedesign, mobilizing on site and pouring the concrete can be limited toa matter of days – and this BIW job was a prime example. A pricewas agreed with the main contractor on Thursday, the letter ofintent received on the following Saturday – and the first pour atground floor level was cast within a 10 day period.The whole project progressed at a similar pace – with all 21,000 m2 of post-tensioned slabs designed, installed, poured andstressed in less than five months from us receiving the go-ahead onthe project. In recognition of our excellent service during theworks, the contractor awarded us the design and installation ofpost-tensioned slab for the associated multi-functional hall. l

BUILDINGS

BIW HOTEL, KINGDOM OF BAHRAIN

Fast and five star

TEAM & TECHNOLOGYOWNER Bahrain Investment Wharf

MAIN CONTRACTOR Al Namal Construction Co.


BBR NETWORK MEMBERNASA Structural Systems LLC (United Arab Emirates)

Local insight:Docklands

The ExCeL exhibition centre sits close to the Isle ofDogs, in the heart of an area defined by its seafaring

and trading past. Although hard to imagine now, LondonDocklands was once a hive of activity, fuelled by thearrival and departure of ships transporting goods fromall over the world. The docks here grew up primarily inthe early 1800s, with later additions in 1880 and 1921.However, by the 1970s, commercial shipping consistedmainly of container ships which required deep waterberths. Thus, the old docks progressively fell into disuseuntil the vision of regeneration was born in the 1980s.Now, the shining Canary Wharf development – duringwhich Britain’s tallest building was constructed – standsas a beacon for regeneration and has established asecond major financial centre in London.

THE SLAB WAS NOMINALLY 240 MM THICK, WITH 475 MM DEEPBEAMS – WHICH COVEREDAPPROXIMATELY 65% OF THE SCHEME...

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46 CONNÆCT

MAKING WAVESThe £19 million new Marine Building atPlymouth University now accommo-dates state-of-the-art research facilities,including the most technically advancedwave tank and testing facilities in Europe.The two giant ocean and coastal wavetanks are – at 48 m by 16 m – nearlythe size of an Olympic swimming pool,and will contain 225,000 liters of water,all suspended from the floor above.During the project, BBR NetworkMember, Structural Systems UK provid-ed post-tensioning expertise for the con-struction of some of the largest concretebeams ever produced in the UK.The structural system chosen wasprecast post-tensioned beams spanning16 m, with secondary spanning 100 mmdeep wide-slab precast unitsincorporating a 125 mm structuralscreed. The 32 beams are 500 mm by750 mm deep at midspan, reducing to400 mm by 690 mm deep at 3.4 m from

1 each column to accommodate a cranefixed to the underside of the beams.Each beam comprised two BBR VTCONA CMI 706 bonded multistrandanchors with single end stressing. Asdeflection remained an issue after initialstressing, a full-scale FE vibration analysisconfirmed a response factor of 3, thiswas accepted by the building client.Transporting the 16.3 m beams to sitewas a logistical feat in itself and requireda specialized trailer and a special highload capacity crane, imported from Asia,on site to lift the beams into position.Beam design also had to consider thedifferent permutations and stressesinvolved in the lifting process. Supporting the beams on a relativelysmall column width meant that thetraditional recess provided for the multi-strand anchor interfered with theanchorage length for the supportreinforcement. Placing the anchorbearing plate on the external face of the

UNIVERSITY BUILDINGS IN THE UK AND AUSTRALIA

Degrees of differenceTwo different university buildings, two different countries –

and two very different challenges. Long after they hadgraduated, engineers from the BBR Network recently found

themselves back on the campus. In both cases, they providedtechnically excellent solutions in some very unusualcircumstances – each one leading edge and perhaps providingfood-for-thought for any engineering undergraduates whohappened to pass by the construction sites!

1

1

47CONNÆCT

beam removed the recess requirement, butleft the anchor exposed. The architectaccepted the detail once a plastic end capwas sourced to minimize the impact of theprotrusion on the building space. We also undertook the in-situ prestressing oftwo 800 mm wide by 1,000 mm deep beamsproviding support for one of the suspendedcoastal tanks. Use of two CONA CMI 706tendons for each beam eliminated threelayers of congested bottom reinforcementand provided a crack-free structure, increasingthe durability and design life of the tank.

VITAL DEGREESMichael Losinski, Design Manager forAustralian BBR Network Member, StructuralSystems Ltd, reports on the engineeringchallenges and development of theconstruction techniques that led to thesuccessful completion of SwinburneUniversity’s iconic Advanced TechnologyCentre in Melbourne.We provided the main contractor with acomplete structure package that includedpost-tensioning design and installation,formwork, steel fixing and concreteplacement. Understandably, SwinburneUniversity was keen to make use of their newfacility and all parties were constrained by anextremely tight design and constructionprogram. The horizontal structure

2

incorporated approximately 120 t of 15.2 mmdiameter slab and beam post-tensioning,stressed to 212 KN per strand. In addition tothis, seven strand vertical multistrand PTtendons were also installed at the extremecorners of each of the service cores tocounteract the large lateral loads generatedwithin the buildings.The large double-height clear span lecturetheater, presented our design team with aseries of unique challenges. To achieve thelarge open space, four complex transferbeams were required at level 3. These were

formed with a maximum structural depth of3.45 m and each was required to spanapproximately 20 m to carry all eight of thelevels above. The BBR VT CONA CMImultistrand system was utilized within thesebeams, with each beam containing a total of93 strands each – or three 31 strand tendons. Stage stressing of both monostrand andmultistrand tendons within the transfer deck was imperative to ensure adequate stress anddeflection criteria were met throughout all construction stages. Monitoring of beamedges was conducted by daily surveys toensure that shrinkage of the transfer beamswas maintained within the calculated limits.Construction requirements and site logisticsrequired that the large transfer beams werepoured as one single element with no

horizontal construction joints. This ultimatelyraised concerns regarding the heat ofhydration generated within the deep beams.Of major concern were the excessivedifferential temperatures that could occurthrough the large depth, potentially generatingstructural voids and failure planes within thebeams. To combat this issue, specific concretedesign mix, formwork and curing procedureswere implemented to monitor and minimizethe calculated temperatures expected. Along with our concrete suppliers, weundertook extensive analysis of the concretemix, and thermocouplers were installed withinall the transfer beams to monitor the heatgenerated. The delivery temperature of theconcrete was imperative in achievingacceptable temperature criteria and, hence,we explored – and later used – cooledaggregates. This additional measure ensuredthat the maximum delivered concretetemperature did not exceed 10 ºC.The formwork remained in place, acting as aninsulator until ambient temperatures in thebeams had been achieved. Curing of the slabsurface was vital to ensuring that surfacetemperatures were kept at a relatively consis-tent rate, compared to that within the beams. Results from the thermocouplers indicatedthe maximum core concrete temperature wasapproximately 52 ºC and the differential tem-perature between core of beam and externalface was minimized to less than 20 ºC. The use of multiple post-tensioned systems,techniques and design considerationsthroughout this structure, ensured thatconstruction continuity could be maintained.Casting transfer beams in one single pourmeant that formwork could be stripped at anearly stage allowing for all contractors tobegin works earlier, thus meeting the tightdeadlines set by the client. l

BUILDINGS

TEAMS & TECHNOLOGIES

PLYMOUTH UNIVERSITYOWNER University of Plymouth

MAIN CONTRACTOR Leadbitter Group



SWINBURNE UNIVERSITYOWNER Swinburne University of Technology

MAIN CONTRACTOR Kane Constructions

ARCHITECT H20 Architects

STRUCTURAL CONSULTANT Watermans

PT DESIGNER Structural Systems Limited

TECHNOLOGY BBR CONA flat BBR VT CONA CMI internal


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DURING THE PROJECT, BBRNETWORK MEMBER,STRUCTURAL SYSTEMS UKPROVIDED POST-TENSIONINGEXPERTISE FOR THECONSTRUCTION OF SOME OFTHE LARGEST CONCRETE BEAMSEVER PRODUCED IN THE UK

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2

48 CONNÆCT

The superstructure of the viaduct comprisestwo tram tracks with platforms and bicycle

tracks. Under the main structure are two railwaylines, a railway station and two carriageways. Alsointegrated into the structure are two lift shafts,stairs allowing communication between levels anda wide ramp leading in the direction of the footballstadium. All elements – apart from the concretesuperstructure and piers – were made usingarchitectural concrete techniques.The main structure was formed from C50/60concrete and has an irregular shape where the

maximum width of the viaduct of29.3 m and minimum is 18.7 m. Themain structure is supported onseven supports, each of which islocated at a different angle relativeto the axis of the structure (39-76 º), which causes a largevariation in span lengths whichrange from 12.2 m to 36.7 m.Beams have different total lengths –from 104.9 m to 163. The structureis post-tensioned with CONA CMI1906 and 2206 tendons. Thesuperstructure was concreted onscaffolding in two stages whichresulted in the use of inaccessiblefixed anchorages, K-couplers and continuous tendonsrunning over the whole length ofthe viaduct.The roof is supported by amongother things, three skews from thevertical walls made of C35/45concrete. The largest wall was post-tensioned using CONA CMI 1906tendons and concreted in twostages. This wall was designed as asingle-span structure where thetendons are located horizontally inthe lower part.The roof is a monolithic prestressedconcrete slab which has a four-sidedirregular shape and was made fromC50/60 concrete. The slab is fixedto three walls and additionallysupported on concrete-filled steelcolumns deviated from the vertical.

The roof has a variable thickness from 50 cm forthe walls, to 24 cm at the end of the 12.75 m longcantilever. The roof is post-tensioned, in bothlongitudinal and transverse directions, with 50 CONA CMM 106 and 197 CONA CMM 406tendons made up of four strands. Each tendon hasa different length from two to 92 m!We used a total of 64.6 t of bonded stressing steelfor the superstructure and 2.9 t for the wall, plus afurther 17.4 t of unbonded stressing steel for theroof. All tendons had cross-sections of 150 mm2

and a tensile capacity of 279 kN.This project admirably illustrates the wide varietyof applications the BBR VT CONA CMX systemoffers and how early collaboration, between thedesigner and ourselves, can result in a veryinteresting and lightweight structure. The use ofpost-tensioning has allowed the construction of aslender – and somehow transparent – structure. Itcan only serve to enhance our environment whenpublic buildings gain attractive and more expressiveforms at the very frontier of architecture andsculpture. While projects like this play an importantrole in our portfolio, it is the work of designersthat really shows how creativity is unleashed by theunlimited possibilities, for making any form ofstructure, offered by the use of BBR technology. l

TEAM & TECHNOLOGYOWNER Gmina Wroclaw

MAIN CONTRACTOR Filar Sp. z o.o.

DESIGNER Arcadis Sp. z o.o. & Ozone & ZNTiWInmost-Projekt

TECHNOLOGY BBR VT CONA CMI internalBBR VT CONA CMM monostrand


One of the many projects connected with the 2012 UEFA European Football Championship to be held in Poland and Ukraine is the construction of railway

junction near the Euro 2012 Football Stadium in Wroclaw. Earlycollaboration at the design stage has enabled the optimal use of theBBR VT CONA CMX system in almost every element of design.Pawel Surman, Site Manager for BBR Polska, describes theversatility of the system and how it can be used anywhere.

Unleashing creativity

RAILWAY VIADUCT, WROCLAW, POLAND

49CONNÆCT

Consumingpassion for LNG

World consumptionof LiquefiedNatural Gas (LNG)

continues to be strong –even in 2009, during theglobal economic slowdown,world LNG trade rose around6.5%. Here, we review themarket and award-winningapproach of the BBR Networkin delivering the specializedcontainment facilitiesrequired by this sector. g

TANKS & SILOS

BBR TECHNOLOGY MEETSLNG DEMANDS

50 CONNÆCT

LNG market outlook

The problems at Fukushima, following the earthquake in Japan,have prompted a review of nuclear policies in many countries

and the outcome of these may ultimately benefit the LNG market.Supply of LNG is also increasing, with new fields coming on-line –and there are many potential new LNG importers too, includingprospective customers in Central and Eastern Asia and EasternEurope.Many agencies have produced reports on future trends within the LNG sector andpoints raised which may be relevant to the BBR Network are summarized below:u LNG import capacity is predicted to grow by 105% by 2015.u By 2015, a further 16 importing markets are set to enter the global LNG trade.u Over the next three years, there will be a 400-fold increase in LNG tankers sailingaround the world.

u Although still in its growth stage, floating LNG export markets are expected toplay a major role by 2015.

u More than US$140 billion will be invested in construction of new LNG exportplants between 2010 and 2015.

As new natural gas reserves are developed and progressively come on-line,appropriate receiving facilities are needed in markets importing LNG. Significantforesight and organization is required in this process – typically, it takes some 5-10years for the planning and construction of import and export terminals.

NORWEGIAN LNG PLANTAt the new LNG processing and storage facility inStavanger – created for energy provider LyseGass – Norwegian BBR Network Member KB Spennteknikk installed the post-tensioning fora new 20,000 m3 tank, using latest Europeanapproved BBR VT CONA CMI internal horizontaland vertical loop tendons.

WORLD’S LARGEST LNG TANKCompleted in 2006, the 188,000 m3 capacityLNG tank at Darwin, Australia was one of thelargest above-ground tanks in the world at thetime. Some 47 m high and approximately 94 m indiameter, the tank comprises a 550 mm thickouter concrete wall and nickel alloy steel lining.Australian BBR Network Member StructuralSystems was engaged to install, stress and groutapproximately 570 t of post-tensioning tendons.International portfolio

In the past decade, the BBR Network has applied its expertise to theconstruction of many massive LNG storage structures – and someprojects have even attracted prestigious awards. Design andconstruction techniques for cryogenic containment were featured inCONNAECT 2007, now we update the BBR Network’s LNG portfoliowith some international highlights.

BBR technology and know-how have been applied innovatively to LNG projects allaround the globe. Consequently, the wealth of knowledge within the BBR Network,specifically relating to the successful delivery of LNG construction, is immense and isroutinely applied as ‘best practice’ for further projects.

THE PROJECT IS OF THEHIGHEST STANDARD AND REFLECTSALL THAT IS BEST IN INNOVATIVEUSE OF CONCRETE IN CIVILENGINEERINGConcrete Society Awards 2008 JudgingPanel – South Hook LNG Tanks,Wales

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51CONNÆCT

TANKING UP IN SPAINOver the past seven years, BBR PTE has constructed four LNG tanksin Barcelona and one in Cartagena as part of Enagas installations andare now constructing a further two tanks for them in Gijon (seepages 52 & 53).

AWARD-WINNING LNG CONSTRUCTIONThe UK’s largest civils project in 2008 was declared the winner in thecivil engineering category of the Concrete Society Awards. The teamfrom BBR Network Member Structural Systems (UK) constructedfive 92 m diameter post-tensioned LNG storage tanks at the SouthHook site in Pembroke Dock in South Wales.

TANKS & SILOS

WORLD’S FIRST OFFSHORE LNG TERMINALThe Isola di Porto Levante offshore LNG Terminal – a Floating Storage and Regasification Unit – is a gravity-based structure (GBS) and wasconstructed in a large dry dock facility in southern Spain.The project attracted a special mention in the 2010 fib Awards for Outstanding Concrete Structures and the judges praised the project for theway in which congested areas were handled and for the high quality of workmanship.BBR PTE developed the post-tensioning works in association with two other companies. The GBS was taken by tugboat to its final destination – 17 km off the coast of Italy.

52 CONNÆCT

The Port of Gijon, on the Cantabrian Seasustains many freight and passenger activitiesand has the facilities to handle a variety ofcommercial requirements. In the generalrankings, Gijon comes in sixth place – but, inoperational terms, it is the fourth largest portin Spain. This project gives the Principality ofAsturias a reception terminal for storage andregasification of 300,000 m3 of LNG whichwill arrive at Gijon by sea. This developmentoffers many advantages – it supports growthof the new energy market in Spain, placesAsturias in a good commercial position andGijon will become an exporting port with astrong international presence.

DESIGN CONSIDERATIONSAs with other tanks built in Spain, securityand resistance are the primary designconsiderations in constructing these newtanks which are designed to withstandearthquakes and strong winds.Construction needs to achieve a very highquality – using only the best constructionmaterials and technologies.The two tanks – built simultaneously – arecylinder-shaped and have an 80 m externaldiameter and are over 40 m high. In eachtank, we used more than 600,000 kg ofpost-tensioning steel, divided into verticaland horizontal tendons.

PRESTRESSING TECHNOLOGYThe prestressing technology selected forthis project was the BBR VT CONA CMIsystem for cryogenic applications which wasused as follows:u four foundation slab rings – 48 CONACMI 2406 anchorages with 131 m longtendons;

u cylinder horizontal wall – 292 CONACMI 1506 anchorages with 130 m longtendons;

u cylinder vertical wall – 136 loops, each85 m long, plus 272 CONA CMI 1906anchorages.

The foundation slab rings and horizontaltendons were formed with galvanized duct.While the vertical loops also have aninferior curve made of galvanized duct, therest of the vertical straight design wasconstructed with jointed eight metersections of 104 mm stiff duct – connectedat the expanded end of the tube, thusallowing a rigid joint to be formed betweensections.

David Olivares Latorre of BBR PTE in Spain provides an insightinto the BBR Network’s most recent LNG project where two tankshave been constructed for Enagas at the Port of Gijon.

LNG TANKS, GIJON, ASTURIAS, SPAIN

LNG to enhance regionaleconomic growth

Technical insight: BBR loop tendons

53CONNÆCT

PUSHING & STRESSINGTo push the horizontal cables, we hung thestrand pushing machine from a crane and theoperators worked from an elevator. Thepushing machine was tied to the tank toavoid any unwanted vibration or movementsduring the operation. Meanwhile, the verticalcable loops were pushed using a flexible ductsituated between the M1906 anchorage andthe pushing machine.Foundation slab rings were stressed beforetank construction and remaining tendonswere stressed during construction to acc-ommodate the forces acting on the structure.The established stressing sequence beganwith some of the horizontal tendons and thenext stage was to stress the first half of thevertical loops. Next, half of the horizontaltendons were stressed, followed by thesecond half of the vertical tendons. Finally, thelowest horizontal cables were stressed besidethe access doors.

GROUTING & BLEEDINGThe chosen cement grout was a thixotropicgrout made with Portland cement I-42.5,thixotropic admixture and water (w/c=0.44).In addition to the standard tests for grout, wemade a battery of inclined tube tests andwick-induced tests to demonstrate the suit-ability of the grout, obtaining excellent resultsin terms of bleeding, change of volume andworkability to latest European EN standards.The method specifically designed for verticaltendons is the wringing method whichconsists of creating a forced bleeding of thegrout by applying pressure, thus forcing thewater out of the tendon through the strandsat the upper anchor head. The result of thisis the complete elimination of any possibleexudation of water at the top of thetendons. l

Design andconstruction of LNGtanks requires specialpost-tensioningdetailing, as featuredin CONNAECT 2007,which includesinternal verticaltendons in the tankwalls. Due to thelimited accessibility ofdead-end PTanchorages at thebottom, theinstallation of 180-degree loop tendonsis the preferredoption.Loop tendons consistof two stressing-endanchorages, each oneconnecting to astraight tendon lengthand bothinterconnected bymeans of a 180-degree curved – orloop – tendon. Designconsiderations meanthat both stressing-end anchorages needto be positionedquite close together,leading to a veryreduced radius ofcurvature. A typicalminimum radius ofcurvature in looptendons might be up

TANKS & SILOS

to 0.6 m – thus, considerably smaller than the minimum bending radius of a normalprestressing strand. The full PT tendon is always subjected to static loading, whichprevents strand-fretting fatigue.The high radial contact pressure of up to 900 kN/m, achieved in the curved section,demands that special care be taken when designing loop tendons:u The curved part of the tendon is made of smooth steel pipe and is pre-bent withspecial techniques to avoid buckling.

u The diameter of the inner steel pipe is increased to limit contact pressure and facilitatestrand installation.

u Effective sealing measures should be applied at the curved-straight duct transition toavoid the ingress of cement paste when concreting.

u The pressure exerted by the strands from the inside of the duct lead to very highradial and transverse forces in the concrete. Additional reinforcement is, therefore,installed on the inner side of the curvature to confine the concrete and properlydisperse those forces through the concrete.

TEAM & TECHNOLOGYOWNER Enagas S.A.

MAIN CONTRACTOR FCC INDUSTRIAL

DESIGNER FCC INDUSTRIAL – DirecciónTécnica + Carlos Fernández Casado



SECURITY AND RESISTANCEARE THE PRIMARY DESIGNCONSIDERATIONS INCONSTRUCTING THESE NEWTANKS WHICH ARE DESIGNEDTO WITHSTAND EARTHQUAKESAND STRONG WINDS. ”

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54 CONNÆCT

The leading sugar company in Central andEastern Europe, AGRANA, has enlarged itsstorage capacity in Tulln – about 40 km westof Vienna – with a new silo. This 70,000 tcrystallized sugar silo is 49 m in diameter and52 m high – and is Europe’s second largestsugar silo. Its operation will largely beautomated, with sugar being handled using a200 m-long conveyor bridge which willconform to latest hygiene and safetyengineering guidelines. In addition, waste heatfrom the sugar production process will beused to heat and condition the silo, thussaving primary energy and associated CO2emissions – the latter will also be saved, astransportation by road to other storagefacilities in Austria or Hungary will no longerbe required.The silo wall is a constant 40 cm thick and forthe post-tensioning, we used the BBR VTCONA CMM 0406 unbonded internalsystem. The tendons were placed at a centredistance of 16 cm in the lower part of thesilo. This meant there were six tendons withfour strands for every one meter of silo wall.Therefore, we placed them in an inner andouter layer within the wall to get a real ver-tical distance of 33 cm between two tendons.The project was ideally suited to slipformconstruction and – with a plan to concretebetween two and 2.5 m in 24 hours – one ofthe challenges for us was installing the cablesquickly enough, particularly in the lower partof the silo. The slipform rig outline wasenlarged by a staircase and an elevator whichallowed us to have a small working platform. The design only accommodated one buttressfor stressing – this meant each tendon wasabout 162 m long and weighed almost a ton! Tendons were produced and cut to length atour workshop near Salzburg, individuallycoiled up, bound and delivered on site. Fromthe working platform, we put a single tendoninto an unwinder. A pusher, similar to strandpushers used for the CONA CMI system,pushed the 0406 tendon forward from oneside and a winch pulled the end of thetendon from the other side. Suspended rollerswere mounted every four to five metersaround the slipform rig to increase the glideof the tendon and keep it in the right position.

Based on excellent previousexperiences and the earlyinvolvement of

Vorspann-Technik GmbH, theBBR Network Member in Austria,the designer decided to use theBBR VT CONA CMM system for anew sugar silo in Tulln.

SUGAR SILO, TULLN, AUSTRIA

Expertise & easy handling

55CONNÆCT

After pulling and pushing the tendon allaround the silo, it was manually lifted out ofthe suspension units and fixed with wire ontothe reinforcement. With this equipment and methodology, threeworkers could install one 162 m tendon inabout an hour – an achievement only attainedbecause of the easy handling characteristicsand installation of the CONA CMM system.Everything worked well – concreting with theslipform rig was finished within 23 days.Stressing was carried out simultaneously atboth ends and generally showed slightlyshorter elongation values than predicted bythe designer. Overall construction time wasabout 11 months and the silo was finished onschedule. In October, when the sugar-beetharvest began, the new sugar silo went on-linefor the first time. l

TANKS & SILOS

IN FOCUS: Sugar beet

The main focus of production in Agrana’s sugar business segment is on themanufacture of sugar products from sugar beet. Sugar beet is a hardy

biennial plant grown commercially for sugar production as its tuber contains ahigh concentration of sucrose. Sugar beets and other Beta vulgaris cultivars –such as beetroot and chard – share a common wild ancestor, the sea beet orBeta vulgaris maritima.The European Union, the United States and Russia are the world's three largestsugar beet producers, although only the EU and Ukraine are significantexporters of sugar from beets. Beet sugar accounts for 30–35% of the world'ssugar production.Sugar beet can be grown commercially in a wide variety of temperate climates.During its first growing season, it produces a large storage root weighing 1-2 kg whose dry mass is 15–20% sucrose by weight. In commercial beetproduction, the root is harvested after the first growing season, as during itssecond season the root decreases in size due to flower and seed production.After reception at the processing plant, the beet roots are washed, mechanicallysliced into thin strips called cossettes and passed to a machine called a diffuserto extract the sugar content into a water solution. This is then followed by threefurther processes – carbonatation, evaporation and crystallization – to producesugar crystals.

TEAM & TECHNOLOGYOWNER AGRANA Zucker GmbH

MAIN CONTRACTORSTRABAG SE & Steiner Bau GmbH

DESIGNER Freund und Vogtmann Zt GmbH

TECHNOLOGY BBR VT CONA CMMmonostrand


56 CONNÆCT

Included in the contract is the constructionof six identical 34.3 m internal diameter35.63 m high LPG storage tanks – three forpropane and three for butane. Concretewalls were designed as 1,000 mm thick atthe bottom and tapering to 500 mm at 7.13 m from the base slab, remaining at 500 mm thick right up to the roof.CB&I had expressed the required long-termprestressing as a function of height along thewall (kN/m) and we were contracted toprovide all methods, shop drawings, material,supervision and specialist equipmentrequired for the supply, installation, stressingand grouting works.The tanks were built with a permanent innersteel liner which was prefabricated andwelded in-situ over the full height of thetank. The concrete wall was thenconstructed in ten equal lifts of nearly 3.5 meach – carried out over 15 day cycles – withconventional timber formwork for theoutside face. The post-tensioning anchorages andcorrugated galvanized iron (GI) ducts wereplaced prior to concreting, while prestressingsteel was installed after the wall pour. Mastclimber platforms were erected to enable PT

works to proceed in an efficient manner,while tower cranes provided the necessaryhoisting requirements for equipment such asstressing jacks.Prestressing was applied to the tank wallusing 52 horizontal tendons made up ofeither 18 or 19 strands. We used the BBRVT CONA CMI 1906 system for cryogenicapplications – with 150 mm2 strands with atensile strength of 1860 MPa, delivering aMinimum Breaking Load (MBL) of 279 kN.All in all, a total of 73 km of GI ducting and1,620 t of stressing steel was consumed. Thetendons were stressed in three stages:

u Stage 1 – Ring beam tendons prior tocasting of the top roof

u Stage 2 – Tendons above TemporaryConstruction Openings (TCOs)

u Stage 3 – Tendons passing through TCOsupon casting and closure of TCO.

Stressing was carried out when the concreteachieved a 50 MPa cube strength, asspecified in our contract.The grouting specification required that thebleeding should be determined by a wick-induced bleed test – as set out in BS EN447:2007 – and, when tested in this way, theaverage of three results for bleeding shouldnot exceed 0.3% of the initial volume of thegrout. The minimum compressive strengthafter 28 days was to be 50 MPa. To achievethis requirement, grout trial mixes wereconducted.The project is being constructed on a fast-track basis and well ahead of its originalschedule – due to excellent coordinationand management by the entire project team– with the works expected to completesome way in advance of the programmedJune 2012 completion date. l

The tally of tanks constructed by Abu Dhabi-based BBR NetworkMember Structural Systems Middle East has recently risen to 17with the award of a contract for the post-tensioning of a further six

LPG tanks in Ruwais, reports Contracts Manager Mahesh Nayak. Thecontract reflects a successful 12-year long working relationship in theUAE with designer and tank subcontractor, Chicago Bridge & Iron (CB&I).

TEAM & TECHNOLOGYOWNER Abu Dhabi Gas Industries Ltd. (GASCO)

MAIN CONTRACTOR Flour

DESIGNER/TANK SUBCONTRACTORChicago Bridge & Iron


BBR NETWORK MEMBER Structural SystemsMiddle East LLC (United Arab Emirates)

4TH NGL TRAIN PROJECT, ABU DHABI, UNITED ARAB EMIRATES

Strengthening relationship with PT

57CONNÆCT

STAY CABLESEurope’s

largestsinglepylonstay

cable bridge

Featuring BBR technology in itsconstruction, a dramatic newstructure, near the confluence

of the Danube and Sava rivers, hasbecome Europe’s largest singlepylon stay cable bridge. The elegantSava Bridge – the third river bridgein Belgrade – will reduce city-centretraffic congestion, as well asunleashing the Serbian capital city’snortherly expansion. g

SAVA BRIDGE, BELGRADE, SERBIA

58 CONNÆCT

The old city of Belgrade was founded onthe south bank of the Danube, on aneasily defensible outcrop of limestone,and spread to the south, east and west.The city now has a population approach-ing two million people and its continuedexpansion northwards has beensignificantly constrained by the limitedcapacity of the existing bridges crossingthe Sava River. This created a bottleneckwhich increased the level of traffic con-gestion in central Belgrade. To reducethe city centre congestion and increasethe capacity of the highway network, athird major road bridge across the SavaRiver was necessary. The new Savacrossing is in sight of downtownBelgrade and passes over the tip of Ada

Ciganlija island. The structure, includingthe approaches, is the largest viaduct ofthe Balkan region, connecting therecently constructed business zone ‘NewBelgrade’ in the north with the historiccentre of Belgrade. The bridge forms anintegral part of the inner semi-ring roadand, for a couple of years, was thebiggest infrastructure project in Serbia.

PROJECT OUTLINEThe overall length of the continuousbridge is 964 m which consists of a 338 m long side span, a 50 m end spanand the main support system, a 576 mlong asymmetric cable-stayed structure.The total width of the Sava Bridge is45.1 m – by comparison, normal six lane

Serbia’s newest landmark owes its reality to an internationaldesign competition held in 2005 by the City of Belgrade.An outstanding solution was sought for a new crossing of

the Sava River – carrying three lanes in each direction, two tracksfor tramways, plus pedestrian and bicycle paths on either side.The winning design was a single pylon asymmetric cable-stayedbridge, which crosses the River Sava in a single span withoutdisturbing the river beneath. BBR Network Member Vorspann-Technik took up the challenge of the stay cableworks, and their Site Manager, Marcel Bartikowsky, presents areview of the project and its challenges.

THE 376 M MAIN SPANIS OF STEEL CONSTRUCTIONSUPPORTED BY 20 PAIRS OFSTAY CABLES ANCHORED ATTHE PYLON AND THESUPERSTRUCTURE.”

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59CONNÆCT

bridges are around 25-30 m wide. The staystructure has a 200 m high cone-shaped pylonwhich was constructed in concrete using self-climbing formwork. The lower section of thepylon is split into two legs which penetratethe deck between the carriageway and railwaytrack. The two legs merge at a height of 98 mand continue as a single circular shaft – wherethe stay bearings are placed – up to a heightof 175 m. For the pylon’s tip – the uppermost25 m – a stainless steel jacket made of sheetmetal is mounted.The 376 m main span is of steel constructionsupported by 20 pairs of stay cables whichare anchored on the pylon and thesuperstructure. The extremely long and heavymain span requires the bridge to be counter-balanced by a concrete back span of 200 m –which also has 20 pairs of stays. A box sectionform was chosen to anchor the stay cables inthe superstructure. The box section is dividedinto three cells – two smaller ones on theoutside with the anchorages and a wider one– carrying all utility lines – in the centre. Thedeck slab is supported by a hollow box girderwhich is 14.5 m wide and 4.75 m high. Theouter 15.25 m wide cantilever slabs aresupported by raked brackets at four meterintervals. The deck of the main span wasformed as a rectangular steel box, also dividedinto three cells, and weighs 8,600 t in total.The deck units were shipped to Belgrade andunloaded in the preassembly yard, close to theside span, where the sub-elements werestored and preassembled into 16 m longsegments.

NO PROPS IN RIVERA stipulation for the bridge’s construction wasthat the main span across the River Savashould be realized without temporarypropping in the river during erection. Thus,the free cantilever method – operated fromone riverbank – was chosen for the erectionof the 21 main span segments. The segmentswere loaded on a barge at the preassembly

yard and shipped to the correct positionunder the bridge. A derrick crane, located atthe tip of the corbel, lifted the segmentswhich weighed up to 360 t each. Afterwelding, the cantilevered deck was completed,the derrick was moved to the new segmentand the new pair of stay cables could beinstalled.

STAY SPECIFICATIONFor the stay cables, we used BBR HiAmCONA 5506, 7306, 8506 and 9106 anchorswhich were preassembled in our specialistworkshop in Austria. The number of strandsinstalled in each cable followed therequirement of the design and the sizes ofthe stay anchorages were chosen to

STAY CABLES

Dipl.-Ing., Holger Svensson, PE, CEng, is aprofessional engineer and former Speaker ofthe Executive Board of renowned consultingengineers Leonhardt, Andrä und Partner(LAP). Recently, he has published a book,Schrägkabelbrücken – 40 Jahre Erfahrungweltweit, about stay cable bridge design andconstruction, based on over four decades ofextensive experience of design engineeringfor major international projects. He nowshares a few thoughts and experiences onthe Sava Bridge project and cable-stayedstructures generally.Sava is an interesting bridge – its form is thatof half a normal cable-stayed bridge, so if youdoubled the size you would arrive at a verylarge bridge indeed. It also has a couple ofunique aspects. Firstly, it’s the largest cable-stayed bridge with a single tower in Europeand, secondly, the sidespan – which doesn’trest on piers over the water – acts as anexact counterbalance to the main span. Originally, the bridge was designed completelyin steel to reduce the weight, because thesidespans could only be supported from theshore. LAP submitted an alternative proposalfor a hybrid bridge with a steel main spanand concrete sidespans – the concrete actingas a counterweight for themain span. This was a reallycompetitive alternative, as itdelivered a significant costreduction for the client overthe steel option.The whole project wentextremely smoothly andcame in on time and onbudget. There were slidingforms for towerconstruction and sidespansconstructed using theincremental launchingmethod – which,incidentally, was invented byLAP in the 1960s. The 45 m sidespans werequite something – involving extremely heavyweights. The 376 m long free cantilevering

main span was fabricated in Asia, shipped tosite, preassembled and installed – not aunique situation, but it went very well indeed.LAP’s relationship with BBR began with thecable-stayed Schillersteg footbridge back in1960. Fritz Leonhardt thought of using BBRtendons for their strength and stiffness and,along with colleagues, developed a systemwhich later became BBR HiAm. This smallbridge, with its parallel wire technology, wasthe forerunner of whole generations of majorcable-stayed bridges which followed aroundthe world.Today, design challenges are largely aroundrealizing longer spans. The trickiest thing withlonger spans is cable dynamics. So, we usethree types of countermeasures – profiledsleeves to avoid rivulet formation, dampers

and thirdly, we have theoption of using cross-ties,although this is preferablyto be avoided.Personally, I believe thecasual observer should beable to see the flow offorces, to understandhow the structurefunctions – many cable-stayed bridges do thiswell. Above all, simplicity– this is a golden rule forcreating a successfulcable-stayed bridge.

On the record:with Holger Svensson

Schrägkabelbrücken-40 Jahre Erfahrung weltweit by HolgerSvensson was published by John Wiley & Sons Limited in2011, ISBN 3433029776, 9783433029770, 450 pages. TheEnglish version will be available in May 2012.

WE COMPLETED OUR TASKWITHIN JUST A YEAR – INSTEADOF THE ORIGINALLYPROGRAMMED 18 MONTHS.

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g

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60 CONNÆCT

accommodate further strands – allowing theinsertion of additional strands, should this provenecessary at some future stage.The cables – each up to 375 m long – consist ofcompacted bundles of parallel seven-wiredstrands. Each individual strand is galvanized andsheathed with polyethylene coating, which is filledwith grease to prevent corrosion. The outerdiameter of the covering HDPE pipes varies from

200 to 280 mm, depending on thenumber of strands. In total, 1,280 tof high grade steel was used forthe 80 cables.

ADVANCING WORKSPROGRAMThe permanent works for thebridge began on 1 April 2009 andfollowed a period of extensiveinvestigation and testing ofmaterials for use in the structures.There was a three yearconstruction program – stay cableworks were scheduled for one-and-a-half years. We planned thepreparation and installation worksfor one set of two back span cablesand two main span cables on athree weeks’ cycle – includingHDPE-pipe welding, strand pre-cutting, cable lifting, strandinstallation and stressing the cableto the required force.However, political pressures meantthat the opening date for thebridge was brought forward to theend of 2011 – much earlier thanoriginally scheduled. So, to meetthe new deadline, we made some

changes to our procedure for strand installationon site. Our solution was to rewind the strandsdirectly from the coil, without pre-cutting them.Thereby, time for installing the cables was reducedand it was possible to finish one set of stayswithin 12 days – including the lifting of pipes,installation and stressing. We completed our taskwithin just a year – instead of the originallyprogrammed 18 months.

INSTALLATION & STRESSINGFirst, we installed the back span cables and thenthe main span cables. The extremely unusual ratiobetween self-weight of the steel (200 KN/m) andsuperimposed dead load (242 KN/m) demandedthat the installation should have a two stagetensioning process – an initial stressing during free

61CONNÆCT

cantilevering and the final stressing insuccessive stages, after completion of themain span erection. Thereby, a portion of thesuperimposed dead load was placed on thesuperstructure and the geometry waschecked. Then, every second stay wasstressed to final force, the achieved alignmentwas again measured and the remainder ofthe superimposed dead load was placed onthe deck. After this, the remaining stays weretensioned to their final force level. The stressing of the strands was completedfrom inside the superstructure, bymonostrand jacks. After a pair of stays had

been tensioned, the cable forces achievedand uniformity were checked by carrying outlift-off tests on a number of strands. To avoidunwanted effects from temperature andsolar radiation, the tests were made early inthe morning and completed by parallelmeasurements of the geometry – pylon anddeck. The required stressing force was set bythe design and had a tolerance of only +/-2.5% within the strand bundle and +/-3%difference from each other, in one stage.

HOLD-DOWN CABLESAt the end of the back span, beside thebearings, we installed hold-down cableswhich were designed to prevent upliftoccurring under any load combinations inthe Ultimate Limit State (ULS) underfactored load. The tensile stresses were keptrelatively small, so that the additional stressescaused by stay bending did not exceed 0.55x GUTS, in total, at the extreme deformationposition. The required stressing was about27 MN per bearing. To cope with thebending stresses, these vertical hold-downcables were of the same type as the staycables. Three stays with 73 strands eachwere arranged at both of the two bearings.

COUNTERING VIBRATIONMany years ago, engineers discovered thatlong stay cables oscillated due to wind, rainand traffic – and, today, methods to counterthese effects are well-established. So, toprevent stay cable vibrations on the newSava Bridge, each stay cable is equipped withBBR Square Dampers at the lower end, justabove the deck. Damper installation tookplace after the second stage stressing,because there would then be no furtherchanges in cable geometry.The largest single pylon cable-stayed bridgein Europe now takes its place with pride –unlocking the potential of the city ofBelgrade and, with its elegant lines, providingan aesthetic addition to the cityscape. l

STAY CABLES

TEAM & TECHNOLOGYOWNER City of Belgrade

MAIN CONTRACTOROgranak Porr Technobau und Umwelt AG

DESIGNER Leonhardt, Andrä und Partner

TECHNOLOGY BBR HiAm CONA stayBBR Square Damper


62 CONNÆCT

In a €25 million scheme, the new bridge over theRiver Minho in the city of Lugo has taken overduties from an old Roman bridge that was no

longer able to withstand the high traffic volumes.Work was completed in record time – eight monthsbefore the programmed completion date – reportsJose Luis Plaza of BBR PTE, the BBR NetworkMember in Spain.

The 195 m long bridge comprises two distinct sections. Firstly, thereis a 95 m length over the River Minho which was constructed as aparabolic arch with a composite deck, supported by hangers. Thesecond section is 100 m long and has two box girder approachviaducts constructed in two spans of 50 m and joining the centralarched span at the western abutment.The lower deck is supported by 24 75 mm diameter stay cableswhich are connected to the parabolic arch – terminating in a forksocket secured by pins at the upper anchorage and in a threadedsocket with a spherical nut at the lower end. During construction, thearch was supported by two temporary towers situated over thesteel deck.Cable installation was performed using two cranes – one to erect thestay cables, the other to allow our technicians to align the fork sockethole with the upper arch anchorage, so that pins could be inserted.Next, a cable was introduced into the steel pipe in the steel deckgirder, until the threaded lower end appeared beneath the loweranchorage.After hanger installation, we began stressing. Four pull bars and fourstressing bridges had been designed to provide symmetricaltensioning to keep the balance of the structure.The cylindrical socket has an external and internal thread. Theexternal one is for the permanent nut and the internal one isdesigned for connecting pull bars. We used four hydraulic jacksworking simultaneously in pairs to carry out the procedure accordingto a prescribed sequence.This was followed by several phases of checking and re-stressingpreviously stressed cables – to compensate for load losses – untilthey reached their final design stress.After all the cables had been stressed and checked, the cables andnuts were protected against corrosion – with protection caps andgrouting wax.To dissipate cable vibrations, neoprene centering rings were installed –once the cables were structurally active and carrying the permanentloads of the structure. After all hangers had been re-stressed andgrouted, the two temporary piers under the arch were removed. l

RIVER MINHO BRIDGE, LUGO, SPAIN

Suspension solution

TEAM & TECHNOLOGYOWNER City Council of Lugo & Ministerio de Fomento

MAIN CONTRACTOR FCC Construccion

DESIGNER FCC Technical Services

TECHNOLOGY Hanger


63CONNÆCT

This work was carried out using two 63 mmdiameter 210 m-long main cables. Duringinstallation, the cables were suspended from a tem-porary cable and transported to the other riverbank by a system of winches and special trolleys. The main cables were then installed and fixed inthe pylon deviators and, at ground level, they wereanchored at the retaining blocks – the tension wasbased on a proper arrangement of anchor bolts ina ‘bridge’ anchorage. During this stage, continuouscontrol of the main cables and all supportingelements was necessary. The 150 m distancebetween the pylons, as well as the river current,greatly complicated the whole operation. Includingall preparatory work, the task took seven workingdays to complete. The suspended steel platformhad been designed to use 98 20 mm diameterhangers. Bars were attached to the main cable withfork anchorages and special clamps. Bar installationtook place just before the steel platform wasconstructed and simultaneously with suspensionwork. The final step was to regulate the length ofthe hangers to maintain the designed level of thefootbridge platform. The main challenge here wasthe limited access to the bearing cable over themain channel of the River San.The footbridge was fixed with 24 mm diameterwind stay cables at six points on each side of thebridge. Ten cables were used – two of which wereleading along the footbridge (steel deviators wereused in the platform plane) and ended on theopposite bank. Stay cable anchoring was providedby fork anchorages, which offered the option oftransferring the forces to the cable – with thetension connector working as a screwdriver. Thedesign strength of 50 kN was introduced with thehelp of special equipment. Minor corrections wereapplied to maintain the footbridge alignment.The most difficult element of the work was theinstallation of the main carrying cables. This requir-ed the use of tailor-made solutions and installationtechnology specially adapted for site-specificconditions. The whole project took seven weeksand the BBR Polska team was on site for 17 days.

STAY CABLES

The contract for supplying and constructing the suspensionsystem for the new footbridge in Witrylow was awarded to BBRPolska whose scope of work here included the installation of

two main support cables, bar hangers – from which a steel deck issuspended – and wind stay cables. Adrian Basta takes up the story.

TEAM & TECHNOLOGYOWNER Commune Dydnia

MAIN CONTRACTOR Mota Engil Central Europe S.A.

TECHNOLOGY Suspension, stay cableHanger

BBR NETWORK MEMBER BBR Polska Sp. z o.o.(Poland)

Adapting toconditions

FOOTBRIDGE, WITRYLOW, POLAND

l

64 CONNÆCT

With a total length of 1.9 km, four lanes– two in each direction – and two tramlines, the Basarab Flyover Bypass willrelieve city centre congestion bydirecting the inbound traffic, from thenorth of the capital, off to the south,west and east, thus keeping it awayfrom the centre of Bucharest. TheBypass has been designed to support4,000 vehicles a day and is expected tobe used by 32 million passengers a year.The main structure is the five spanBasarab cable-stayed bridge. The spanlengths are arranged as follows – 57 m + 75 m + 168 m + 36 m + 30 m. The first two spans serve ascounterbalances for the stay cables onthe 168 m main span and the remainingtwo spans are not cable-stayed.

COMPLEXITYA number of factors serve to makethis stay cable bridge a complexproject:u It has an irregular, somewhatunsymmetrical, plan shape, bothlongitudinally and transversely – with ramps that enter and exitthe lintel.

u It is a large bridge with a main spanof 168 m and a single tower whichwould be equivalent to a bridgewith two towers and 340 m span.

u It is in a seismic zone.u It has two types of load – road andtrack – as well as a covered stationin the centre of the main span.

u Its main span crosses over railwaylines near the North Train Station.

STAY CABLESThe Basarab Bridge is a steel stay cablebridge featuring the BBR HiAm CONAstay cable system with 30 front stays and30 back stays.The stays – with sizes from 31 to 109strands – were executed with 15.7 mmgalvanized, 1860 MPa GUTS waxedstrands, individually sheathed with aHDPE coating – providing a triple cor-rosion protection system – and enclosedin a white UV-resistant HDPE stay pipe.Due to the large variety of stay cablesizes, a wide range of elements in differ-ent sizes were necessary. For example:u Anchor heads – 60 Uni Headanchorages and 60 Nut Headanchorages, 11 different sizes.

u HDPE stay pipe – a total length of4,865 m distributed in HDPE pipeswith seven different outsidediameters.

u AV deck pipe – seven differentmodels of anti-vandalism deck pipefor a total of 60 cables.

u AV pylon pipe – 60 different modelsof anti-vandalism pylon pipe.

BASARAB FLYOVER BYPASS, BUCHAREST, ROMANIA

Avantgardeconnections

In the centre of the city, two 80 m high pylons, part of the largeinfrastructure Basarab Flyover Bypass, emerge from the bustleof the city. This project has become a tremendous boost for

other projects due to start in Romania over the next few years,transmitting the values of progress and innovation associatedwith it. Gustavo Delgado Martin from BBR PTE, the BBR NetworkMember for Romania, outlines this avant-garde project.

STAY CABLES

65CONNÆCT

ANCHOR HEADSWork started with the installation of the anchorheads. The Uni Head anchorages were installedon the deck, while in the pylon we used 60 mmadjustable Nut Head anchorages, allowing 20 mmfor stressing and 40 mm for unstressing.The upper anchors transfer their load to thepylon under transverse post-tensioning – pairs ofcurved tendons embracing each anchor level. Weused the BBR VT CONA CMI system for thispost-tensioning element.The next job, prior to stay cable installation, wasthe preparation of the strands. A 160 m tablewas set up at the back of the bridge for cuttingthe strands to the required dimensions andpeeling the HDPE sheathing at both ends.Simultaneously, mirror-welding for the HDPE staypipe assembly was being carried out. After liftingthe HDPE stay pipe, the installation of the staycable began.

INSTALLATION CHALLENGESInstallation was performed using the strand-by-strand method, whereby a strand pushingmachine placed at the top of each pylon raiseseach strand from the deck, up towards the pylon.When the strands reached the correct position,they were individually stressed from the deckwith a mono-strand jack using the BBRISOSTRESS tensioning method.For us, the critical issue was the installationprogram – we started the installation of the firststrand on 29 September 2010 and we had tofinish before Christmas. A total weight of 439 t ofsteel strand – comprising 2,392 strands of lengthsbetween 42 m and 164 m – had to be installedand first stage stressed (6-10% GUTS) in lessthan three months!One major challenge was the fact that the staycables could not be assembled and stressed

HIAM CONA ANCHORAGEOPTIONSUsually, the end of the stay cable fromwhich the tensioning is performed –the stressing end – is fitted with anadjustable Nut Head anchorage. Theopposite end, or the dead end of thecable, is typically fitted with a UniHead or BBR Pin Connector.The ring nut of a Nut Head isscrewed onto the anchor head, whichtransfers the cable loads by contactpressure onto the support structure,whereas the Uni Head optiontransfers the load directly to thesupport structure.The HiAm CONA Nut Head comeswith a typical adjustability of 0, 60 or120 mm.In addition to the standard anchorageconfiguration, a compact configurationis available for special applications –such as cable replacement – and hassmaller openings in the bearing plate.

BBR ISOSTRESSThe installation of the HiAmCONA stay cable system istypically carried out on siteusing the strand-by-strandinstallation method.After preparatory cable work –including installation of lower(deck) and upper (pylon)anchorage, strand pre-cuttingand peeling and stay pipeassembly – is completed, thecable is lifted using two master strands to the anchorage locations. The two strandsneed to be cut to a longer length to account for the catenary effect. After stressingof the master strands, each individual pre-cut strand is pulled up through the staypipe to the upper anchorage, before it is guided and fixed in the deck anchorage.Then, the strand is immediately tensioned with a mono-jack using the BBRISOSTRESS method.The BBR ISOSTRESS method requires two different stressing phases – stressing andadjustment. In the stressing phase, each single strand is tensioned to achieve apredetermined elongation which depends on the final load in the stay cable, deckand pylon stiffness, etc. The adjustment phase is carried out either with a mono- ormulti-strand jack to ensure the correct final bridge deck geometry.The BBR ISOSTRESS method ensures an equal stress distribution among the strandsof an individual cable and complies fully with latest stay cable recommendations suchas fib Bulletin 30 or PTI.

Technical insight: HiAm CONA anchorage options andBBR ISOSTRESS

A NUMBER OF FACTORS SERVETO MAKE THIS STAY CABLE BRIDGEA COMPLEX PROJECT“

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66 CONNÆCT

simultaneously, it had to be done individually.And there was one more problem – winterwas fast approaching. With shorter workingdays because of diminishing daylight hoursand temperatures below zero degrees,finishing the installation on time was a realchallenge. In addition, 20% of the stay cableswere placed over live railways – so theirinstallation took more time because of theneed for extreme precautions and safetymeasures in this area. In spite of everything, we did it! On 16 December, just after the installation of thelast strand, a heavy snowfall began – itseemed that the snow had waited for us tofinish!It was very important to finish on timebecause the tension in the strands achievedby first stage stressing allowed the deck slab

to be cast. Casting the deck took threemonths and when it was finished, the secondstage stressing was performed – stressingfrom the pylon this time. A secondadjustment in some stays was needed tocomplete the stressing work.The only remaining task was the closure ofthe stays and the injection of sockets and

protection caps. The injection work wascarried out meticulously to ensure the steelelements were protected against corrosion.With this injection, and successful testingincluding a leak tightness test to the latestinternational standards on the BBR HiAmCONA system, we can reasonably assume a100-year service life for the stay cables.The BBR VT CONA CMI post-tensioningsystem with multi-strand 1906 to 3106anchors has been used in the construction ofall the concrete viaducts that access thecable stay bridge. The connection betweenstages was achieved with single planecouplers. The length of the viaduct meantthat a total quantity of 665 t of PT strandwas installed.

FURTHER WORKThe main structure of Basarab FlyoverBypass was the cable-stayed bridge, but therewas another task performed by BBR for thisproject.At the end of the bypass, opposite the staycable bridge, there is an arch bridge over theDambovita River. We collaborated in itsconstruction by assembling and stressing thehangers which provide a connectionbetween the two arches and the deck. This

WHEN THE STRANDSREACHED THE CORRECTPOSITION, THEY WERE INDIVI-DUALLY STRESSED FROM THEDECK WITH A MONO-STRANDJACK USING THE BBR ISOSTRESSTENSIONING METHOD.

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STAY CABLES

67CONNÆCT

connection was performed by ten vertical hangers on each arch. Thehangers were stressed by stressing the PT bars placed in the lowersteel anchorages. Yet another job realized by BBR on this project was the launching ofa section of the steel bridge over railway tracks. The proximity of thestructure to the railway network made it impossible for installation bycrane, so launching techniques were necessary. This highly specializedheavy civil engineering work was the subject of an earlier article –see CONNAECT 2011.The Basarab Viaduct is set to become Romania’s benchmark forinfrastructure construction, now that the benefits of innovative post-tensioning and cable-staying techniques, developed by the team atBBR PTE, have been fully explored and recognized during theevolution of this complex structure. l

PEDESTRIAN BRIDGE, BLACKBURN, SOUTH AFRICA

HIGHLIGHTINGCAPABILITIES

The Blackburn Pedestrian Bridge – one of thelongest cable-stayed pedestrian bridges on thecontinent – has recently been recognized with a

prestigious Fulton Award. Structural Systems Africaprovided specialist stay cable and post-tensioningservices to the project which featured in the lastedition of CONNAECT.During the 2011 Fulton Awards, the Concrete Society ofSouth Africa declared the Blackburn Pedestrian Bridge theoverall Winner in the Civil Engineering category.Among many aspects of this project, which features the BBRHiAm CONA Pin Connector, the judging panel were“impressed by the careful attention to design and detail, whichwas necessary due tothe uniquely shapedpylon.” They alsocommented that: “Thetowering pylon andfanning stays of thebridge highlight thecapabilities of civil engin-eering and constructionin South Africa.”The judges praised notonly the project itself, butalso the way in whichthe professional teamconsulted and interactedwith the community. l

TEAM & TECHNOLOGYOWNER South African National Highways Agency Limited (SANRAL)

MAIN CONTRACTOR JT Ross / Devru Construction JV

DESIGNER SSI Consulting Engineers

BBR TECHNOLOGYBBR HiAm CONA stayBBR Pin ConnectorBBR VT CONA CMI internal

BBR NETWORK MEMBERStructural Systems (Africa)

Basarab Flyover Bypass recordsu The longest cable-stayed bridge in Romania (355 m)u One of the widest cable-stayed bridges in Europe (43.3 m)u The longest bypass in Bucharest (1.9 km) u The largest intermodal point in Romania.

TEAM & TECHNOLOGYOWNER City Hall of Bucharest, Romania

MAIN CONTRACTOR Basarab JV (FCC Construccion & Astaldi)

DESIGNERS Carlos Fernandez Casado S.L., SpainFHECOR, SpainC&T Engineering S.R.L., Italy

TECHNOLOGY BBR HiAm CONA stayBBR VT CONA CMI internal

BBR NETWORK MEMBER BBR PTE, S.L. (Romania)

68 CONNÆCT

Keeping road traffic moving on the DN1 – amajor national north-south route – as well asstreamlining the junction area of the existingOtopeni Bypass has driven the need forimprovements around the DN1 and theBucharest ring railway. To realize this, a multi-level intersection over the railway tracks andan overpass with four lanes was necessary.Until the construction of the new bridge, roadtraffic in this area ran to the right of therailway line, to a level crossing across theDN1, after which it continued on the left side

of the railway. The lanes connecting the DN1with the Bucharest ring road and the road to-and-from Otopeni, also met at this levelcrossing. The junction was completelyoutdated, given current traffic flows, and oftencaused road congestion – especially when thelevel crossing gates were closed. The bypass over the railway lines hassubstantially improved the traffic flow in thisintersection area, eliminating the queues andtraffic jams at the junction. The final solution for the design of theoverpass was a cable-stayed bridge with atotal length of 240 m and spans of 35 m + 85 m + 85 m + 35 m. The deck needed tobe of a shallow depth because of theclearance required above the railway lines. Todecrease the span length, a large pylon wassited in the centre of the bridge, breaking thecentral span into two sections. The design of

the pylon permits railway tracks to passbetween its shafts. As the bridge is close toBucharest’s Henri Coanda Airport, the pylonheight has been limited to 48 m to complywith aviation safety requirements.Bucharest is in a highly seismic area, thus themain requisite was to minimize the mass ofthe structure. Accordingly, the pylon wasdesigned with a hollow section of minimalthickness – apart from the area close to thefoundations which has been designed as a fullconcrete section. Also, two steel cross beamsbetween the pylons play an important role inthe new structure’s transversal seismic stren-gth. Both the connection between the twosections of the pylon and the connection be-tween the pylons and the cross beams, wereexecuted with post-tensioned high tensilesteel bars. The post-tensioning and injection ofthese bars was also carried out by BBR PTE.The deck and pylon are joined by 32 BBRHiAm CONA stay cables ranging in sizebetween 20 and 34 strands and lengths from32 to 95 m. This amounted to a total quantityof 72.5 t of steel strand for the stay cables,with a ultimate tensile strength of 1860 MPaand strand cross-section of 150 mm2.The main operations – lifting of the HDPEstay pipe, threading and first stressing of thestrands with the mono-strand jack – werecarried out in only 20 working days! Totalexecution time, including the stressing withmulti-strand jacks, the injection of the socketsand protection caps and the installation of theanti-vandalism pipes, was just two months –setting a new record. l

The cable-stayed Otopeni Bridge over Bucharest’s ring railway is –as well as being the second largest infrastructure project in thecity after the Basarab Flyover Bypass – the third longest stay cable

bridge in the country. Ana Contel, Romanian BBR Network Member, BBRPTE, describes the project.

TEAM & TECHNOLOGYOWNER CNADNR SA-DRDP, Bucharest

MAIN CONTRACTORJV – FCC Construccion & Alpine Mayreder

DESIGNER FHECOR

TECHNOLOGY BBR HiAm CONA stay

BBR NETWORK MEMBERBBR PTE, S.L. (Romania)

Untangling the trafficOTOPENI BRIDGE, BUCHAREST, ROMANIA

69CONNÆCT

SPECIAL APPLICATONS

Sinkingwith success

2ND COENTUNNEL, AMSTERDAM, NETHERLANDS

The existing Coentunnel carries some 120,000 vehicles daily under the Noordzeekanaal, but itnow forms a bottleneck on the A10 motorway, with long queues every day. A new immersedtube tunnel is under construction to improve traffic flows around Amsterdam. Ben

Grundlehner of BBR Network Member Spanstaal explains the major role that BBR technology isplaying in the creation of the 2nd Coentunnel. g

70 CONNÆCT

The new structure was to be constructed withimmersed tube tunnel elements – built in theexisting dry dock at Barendrecht and transportedto the tunnel site where they would besubmerged. Four elements were required – eachover 178 m long and consisting of seven sections,

each of the latter were around25.5 m long, almost 30 m wide andmore than eight meters high.Construction of one section tookabout a month – the four elementsonly just fitted in the dry dock, so

good workspace and materials planning was vital. During transportation and immersion, large forcesarise on tunnel elements – and this is critical atsection joints. So, it is now common practice toconstruct post-tensioned tunnel sections.Although at first PT tendons only performed atemporary function – during transportation andimmersion – since the mid-1980s, they have beenused to give more permanent strength to tunnels.In the early days, the tendon ducts were notinjected with grout and it was possible to removethe tendons after immersion – the thinking wasthat they could be used again for future tunnelconstruction activities. The modern view oftunnel design is that post-tensioning plays anenduring role, whereby ducts must be grouted toachieve a bond between the PT steel and theencased concrete and thus creating greaterstrength from their synergy. Also, grout suppliesthe protection needed against corrosion. Thisworking method presented two challenges:u To conquer the friction between the bottom ofthe tunnel and the dry dock (working) floor,grouting operations would mainly be carriedout after the dry dock had been flooded.

u To avoid the unverifiable forces after immersion,often the grouted cables would be severed atjoints between two adjacent segments, so that atunnel element could settle down onto thesubsoil.

Tunnel construction in the Netherlands

Its position – on the North Sea and at the delta of the Rhine and Maas rivers– means that water has always been an important consideration in creatinginfrastructure in the Netherlands. Tunnels play a vital role in providing river

crossings, where sometimes ocean-going vessels or occasionally inland shipsin rivers and canals influence the way these are delivered. This is why mosttunnels in the Netherlands are built using ‘immersed tube’ tunnel methodology.The first river-crossing with a rectangular concrete cross-section to be builtusing the immersed tube method was the Maas Tunnel in Rotterdam whichopened in 1942. Since then, dozens of road, railway, metro and also pipelinetunnels have been constructed here using this method. Our experience hasalso been exported to other countries – including the UK, Germany, Denmarkand Korea. Typically, tunnel elements are constructed in temporary locations – rather thanon the alignment of the finished tunnel. They are built in a dry-dock andfloated out to their final positions on the river crossing. Here, they can be sunkto the right depth and place in a very short time, thus presenting only minordisruption to shipping.During the last 50 years, technology has changed dramatically – making itpossible to prefabricate and transport longer-and-longer elements. Forexample, the first Coentunnel – built in 1961 – had six 90 m long immersedunits. Now, almost five decades later, the second Coentunnel is beingconstructed with four 178 m long immersed units.Many dozens of tunnels have been constructed in the Netherlands, themajority of these were built using immersed tunnel sections which were post-tensioned for transportation. Most of the associated post-tensioning workswere carried out by Spanstaal – using diverse and flexible BBR technology.

Rijkswaterstaat, the government body responsible for ensuring the smoothflow of traffic and water on national networks, awarded a €500 million30-year design, build, finance and maintain (DBFM) contract – which

includes construction of the second Coentunnel – to the Coentunnel Company.

71CONNÆCT

PT TACTICSThe selection of the Barendrecht dry dock –necessitating transportation by sea –combined with the choice of four 178 mlong tunnel elements meant that large post-tensioning forces had to be delivered.We used 1906 BBR CONA tendons – andinstalled 38 tendons for the two outermostelements and 44 for the two innermostelements. Each tendon consisted of 19 15.7 mm diameter strands of 1860 MPa steelquality and strand cross-section of 150 mm2.This delivered a post-tensioning force perelement of 161,000 kN and 187,000 kNrespectively – roughly equally divided overthe roof and bottom of the segments.The tunnel elements were fabricated in twoproduction streams of two elements each.Before casting of the bottom and roofsections, 100/106 mm diameter ducts wereplaced and, at the same time, anchor platesfor the post-tensioning tendons wereinstalled. So-called ‘de-bonding tubes’ wereplaced at section joints. These measuresensured that prestressing forces could beintroduced smoothly into the concrete.After finishing the tunnel elements, the PTtendons were placed, using the strand-by-strand installation method and with the helpof a pushing machine. Then the cables werestressed until they reached the requiredforce. Normally, prestressed tendons wouldimmediately be injected with grout now, togive them corrosion protection – however, in this case, it was not possible.Pressure created during prestressing causesshortening of the concrete. This shorteningwould have been prevented between thetunnel bottom and the dry dock floor. If theduct had been grouted in this position, thenthe prestress forces in the joint would havebeen reduced. This was resolved by groutingthe ducts – from a pontoon – when thetunnel elements were partially floating in theflooded dry dock.

TRANSPORTING ELEMENTSAfter producing the four tunnel elements,preparations were made to transport themfrom the production site in Barendrecht tothe building site in Amsterdam. First of all,the four elements were provided withtemporary watertight bulkheads at bothends, allowing them to float duringtransportation. To facilitate this, each elementwas longitudinally prestressed to ensure that,during its three day voyage, the construction

remained watertight – even when exposedto waves in the sea. The route was acrossthe River Maas from Barendrecht, to Hoekvan Holland and further across the NorthSea to the locks of IJmuiden and finally, acrossthe Noordzeekanaal to Coenhaven inAmsterdam – a total distance of 160 km.

SEQUENCE OF EVENTSAt the end of January 2011, the dry dockwas ready for flooding and then several taskswere executed, including the grouting ofducts. In March, the four tunnel elementswere individually transported to Amsterdam.In April, the first element was submerged –the last element was sunk at the end of May.Consequently, the post-tensioning tendons atthe section joints were severed. Thus, the

prestressing had completed its work for thetransportation and immersion phases andnow continues to contribute to the strengthand stiffness of each section. It is expectedthat the second Coentunnel – together withthe new Westrandweg – will be opened totraffic in 2012 and together they will providebetter traffic circulation and access forvehicles in-and-around Amsterdam. l

SPECIAL APPLICATIONS

TEAM & TECHNOLOGYOWNER Rijkswaterstaat

MAIN CONTRACTOR Coentunnel Company

SUBCONTRACTOR & DESIGNERCoentunnel Construction


BBR NETWORK MEMBERSpanstaal B.V. (Netherlands)

…THE PRESTRESSING HAD COMPLETED ITS WORK FOR THETRANSPORTATION AND IMMERSION PHASES AND NOWCONTINUES TO CONTRIBUTE TO THE STRENGTH AND STIFFNESS OFEACH SECTION.

“”

72 CONNÆCT

Each bridge pier is supported by three 1,200 mm diameter bored piles and two 750 mm diameter raked bored piles. Groundconditions meant that it was not practical –and costly – to carry out a maintained loadtest using concrete blocks for kentledge. Theinitial pile test – using the biaxial loadmethod, with an embedded hydraulic jack – had been unsuccessful.

The test load of the pile was 1800 t – twicethe working load. A new pile was installed toact as an anchor pile and replace the failedone which was at the edge – the center pilewas selected for the next test.Anchored nearer to the test pile, the newpile would experience higher pulling forcesdue to the smaller lever arm. Considerationof the forces for both anchor piles wasreflected in our geotechnical design. Strandswere embedded in the anchor pile during thebored pile construction. A steel plate girderwas placed over the anchor piles and post-tensioned to them. Load was applied to thetest pile by jacking the top of the test pile tothe soffit of the plate girder.The anchor piles were subjected to high pull-out forces during testing – and had beenanchored more deeply than the test pile forthis reason. Additional main reinforcement tothe bored pile was required at the rocksocket region to control tensile stresses andminimize structural cracking during testing.Each anchor tendon was preloaded to

40% UTS before commencing the load testto reduce the elongation of strands duringtesting which, if excessive, would have liftedup the test beam.Each anchor pile consisted of four BBRCONA 1906 tendons, with their dead endanchorages inside the rock socket region. The strands near the top of the pile weredebonded by installing the PE sheath to adepth of 25 m. Two hydraulic jacks, with a 2,000 t combinedcapacity, were used to jack against the testpile and plate girder. At each loadincrement/decrement, the deflections weremonitored over three load cycles. The installation of the long, heavy tendonsinto the anchor pile was a challenge. Theywere tied to the reinforcement cage of thebored pile and the dead ends were staggeredto avoid congestion and ease concreting. Theentire assembly was lifted and loweredcarefully into the bored hole. The project team wanted a strong plategirder which could be assembled in easilytransportable modules. We achieved this bydividing the girder into two separate steelbox girders – each 1,000 mm wide, 1,600 mm high and weighing 20 t. They werelaced together at the top and bottom of theplate girders using channels to ensure theybehaved monolithically under loading. l

RIVER DANUBE BRIDGE, VIDIN –CALAFAT, BUGARIA & ROMANIA

VESSELIMPACTPROTECTION

The new major road andrail bridge being builtacross the River Danube

in eastern Europe will boosttraffic links between Bulgariaand Romania. Crossing thisnavigable waterway, however,means that vessel impactprotection is needed for thebridge piers, Enrique Aranafrom BBR PTE describes thescheme and their work.

The new crossing which includes a mainbridge with three 180 m long extradosedspans, is on transport corridor IV of theTrans-Europe Network and linksGermany to Turkey through Romania,Bulgaria and Greece.The new river crossing connects the townsof Vidin, in Bulgaria and Calafat, in Romania.At this point, there is an island in the RiverDanube which makes a convenient stop-over for the bridge and enables it to bedivided into three main sections.First, there is a low-level rail approachviaduct with 40 m long spans on theBulgarian river bank, next comes a 612 mlong viaduct over the non-navigablechannel that has eight spans, of which allbut one are 80 m long and finally a single-cell box girder bridge over the mainnavigation channel. This main bridge hasfive spans – three spans of 180 m, one of124 m and another of 115 m. The 400 mlong low-level viaduct serves to align theroad and rail lines correctly as theyapproach the main crossing.To protect the bridge piers from vesselimpact, 152 precast prestressed concreteunits are being installed. On the bridgesection over the navigable waterway, eachof the four pile caps – on which thebridge piers will be formed – will beprotected by 38 units. Seven differenttypes of unit are being cast in the onsitecasting yard. The ‘heavy’ ones weigh 120 t

When problems arose with pile testing on the three span Siol River Bridge inSarawak, Tie King Bang of BBR Construction Systems Malaysia, reports that

they were asked to take over piling operations and provided innovations whichrescued the situation. He describes how a successful and economic method forlarge diameter pile testing can be provided by applying post-tensioning to verticalreaction piles with a horizontal steel beam.

SUNGAI SIOL BRIDGE, MATANG, SARAWAK, MALAYSIA

TIMELY TESTING SOLUTION

TEAM & TECHNOLOGYOWNER Public Works Department, Sarawak

MAIN CONTRACTOR Zecon Berhad

TESTING DESIGNER/CONTRACTORBBR Construction Systems (M) Sdn Bhd

BBR TECHNOLOGY BBR CONA internal


73CONNÆCT

and the ‘lighter’ ones are 70 t each.In the yard, two structures have beendesigned for vertical storage of the units(which is the correct position for installation)and these stand close to the jetty crane forease of loading onto the mobile pontoon. Toallow this storage, they are turnedhydraulically from horizontal to vertical.When both units have been loaded onto thespecial structures welded over the pontoon,the pontoon travels a distance of more thantwo kilometers to the pile cap – a journey of

around 45 minutes. On arrival, the pontoonis positioned and secured to the pile capstructure.A purpose-designed steel structure then liftsand positions the units correctly on the pilecap. Three 250 bar 85 t heavy lifting jacks atthe top of the structure carry out the lifting,turning and positioning maneuvers.Joints between the pile cap and the vesselimpact protection require filling with mortarand we are carrying out a two phasegrouting process. When the prestressing of

the units has been completed, the structuremoves to the next pier cap – by which timethe next units will be ready. l


TEAM & TECHNOLOGYOWNER Republic of Bulgaria: MT-PIMU

MAIN CONTRACTOR FCC Construccion S.A.Klon Bulgaria

DESIGNER Carlos Fernandez Casado S.L.

TECHNOLOGY Heavy lifting

BBR NETWORK MEMBERBBR PTE, S.L. (Romania)

74 CONNÆCT

Wellington Dam is owned by the WaterCorporation of Western Australia and wasconstructed on the Collie River in 1931 as amass concrete gravity structure. Originally 19 m high and 232 m wide, the dam wall wasraised one meter in 1944 and an additional15 m in 1960, to give the dam its present 34 m height, with a total wall length of 366 m. The dam has a capacity of 186 millionkilolitres when full and provides irrigationwaters for the region’s farming community.As part of the Water Corporation’s state-wide dams safety and maintenance program,

important works were required to bringWellington Dam into line with currentengineering standards. In response, a processof identifying, analyzing, evaluating and cullingof various options was undertaken to eitherstrengthen, replace or lower the dam. Thefinal design incorporated 43 permanentground anchors to strengthen the existingconcrete gravity structure, as well as anaccess bridge for both the construction andfuture servicing of the anchors.The Wellington Dam Alliance was formedbetween Leighton Contractors, Structural

Systems, Entura (dam design consultants) andAECOM (bridge design consultants) inpartnership with the Water Corporation. TheAlliance designed the access bridgeincorporating a deck that would ‘wash away’during a peak flood event to ensure thedam’s safety.The design of the bridge is unique in severalways. The bridge piers serve the dualpurpose of supporting the bridge deck aswell as housing and protecting the anchorheads. To ensure retention of the bridgedeck’s ‘wash away’ capability during extremeflood events, Teflon bearings and an adjustableHDPE guide system were developed.

ACCESS CHALLENGEThe significant challenge of the bridgeconstruction work was gaining safe access tothe dam’s spillway and, for this, extensivetemporary works were commissioned. Theseworks included a low-level platform whichserved to provide access to the bridge piersduring construction, as well as providing a railfor task-specific construction trolleys to runon. A series of trolleys were developed whichran on the access platform rail and a secondrail fixed to the spillway crest. The trolleyswere fitted with overhead monorail hoists tocomplete the tasks of initially constructing theaccess platform as they advanced, wire sawingand concrete removal for the bridge piernotch, drilling and installation of starter barsto the notch, plus the reinforcement,formwork and concrete placement for thebridge piers. The pier construction work wasassisted with lifting capacity for formwork,

Australian BBR Network Member Structural Systems is continuingits recent run on high capacity ground anchoring projects withthe remedial works to Wellington Dam in the south west of

Western Australia. The existing concrete gravity structure has beenstrengthened with the addition of ground anchors, using BBR VT CONACMG technology with anchors of up to 91 strands – equaling the currentworld record capacity. Mark Seisun, Project Manager, takes up the storywhich was first reported in CONNAECT 2011.

WELLINGTON DAM, COLLIE, WESTERN AUSTRALIA

75CONNÆCT

reinforcement and concrete by50 t crawler cranes that wereinstalling the precast concretebridge decks close behind theadvancing pier construction. Twoconstruction teams advancedfrom either side of the dam,constructing the bridge to meetat the spillway’s midpoint.A specialist drilling contractorwas engaged on the project todrill the 355 mm diameter holeswith a purpose-built drill rigutilizing a down-the-holehammer.Our team was focused on thefabrication, installation, groutingand stressing of the 43permanent ground anchors. Theanchors were the same design aswe used on our recentlycompleted dam projects atCatagunya and Tinaroo andincorporated BBR VT CONACMG technology for vertical

anchor sizes of 31, 42, 55, 65 and91 x 15.7 mm (279 kN MBL)strands. The 91 strand anchorsequal our previous world recordcapacity anchors installed atCatagunya in 2010 with an MBLof 25,389 kN. The anchors aremonitorable and restressablewith a design life of 100+ years.Anchor lengths varied from 64.2 m maximum to 18.4 mminimum.

PIVOTAL ANCHORTECHNOLOGYThe availability of the highcapacity CONA CMG 9106anchor technology was pivotal tothe design’s viability. The finaldesign required two 9106anchors per 50 ft wide concretemonolith across the spillway. As the bridge piers double asanchor housings, the number andlocation of piers was determined

by the anchoring requirements.A reduced anchor capacitywould have required increasedanchor numbers and sub-sequently increased the numberof bridge piers from 30 to 45 –significantly impacting on spillwaydischarge characteristics andultimately the solution’s viability.The anchoring workscommenced in November 2010and were completed in June2011 – two months ahead ofprogram. The on site anchorfabrication facility used purpose-built equipment to grease andsheath with HDPE eachindividual strand’s free lengthwith the bare bond lengths (upto 12 m) being steam cleaned tomaximize bonding to the grout.The individual strands wereassembled into the completedanchor using a series of spacersand strapping to the bond zoneto form an hourglass effect,maximizing the load transfer intothe surrounding rock, via the highstrength grout.

The completed anchor wastransported on public roads tothe dam wall on a series of up to30 purpose-built trolleys,negotiating some difficult bendsand steep declines along the way.Anchor installation wascompleted in two stages. First the 280 mm diameterHDPE outer sheath was installed.This consists of an HDPE g


Leaders in ultra-highcapacity anchors

Facts & figuresu Permanent anchors = 31-91 x 15.7 mm diameter strandsu Vertical anchors = 18 or 64 m long eachu Bond length = 12 m eachu Drill hole size = 355 mm diameteru Minimum breaking load = 25,389 kNu Test force = 19,042 kN (75% MBL)u Lock off load = 18,280 kN (72% MBL)u Design working load = 16,503 kN (65% MBL)u Strand tonnage = 230 tu Class G Oilwell Cement & GP cement = 221 t

76 CONNÆCT

corrugated sheath over the bond length with7.5 m lengths of HDPE smooth sheathingfusion-welded on site to form the free lengthsheath. As this sheathing is the primary formof corrosion protection for the anchor, itsintegrity is critical and it is pressure testedwith water to detect and allow the repair ofany leaks that may be observed. Installation of the anchor into the installedsheath was achieved with a custom frameand a 17 t braking winch to control the rateof descent. The anchors were suspended inthe hole during the grouting process whichuses Class G Oilwell cement to the bondlength and GP cement to the free length.

TAILOR-MADE STRESSING JACKFollowing 28 days minimum grout curing time,the anchors were stressed using a purpose-built 2,200 t capacity hydraulic jack. Typicallyeach 9106 anchor was proof loaded to 75%MBL (19,042 kN) and locked off at 72% MBL(18,280 kN). With the recent development ofthe low-friction strand entry transitions to theBBR VT CONA CMG anchor heads, excellentresults have been achieved during stressing.No strand or wire failures have occurredwithin the three projects (168 anchors)where we have used this technology todeliver the world’s highest capacity permanentground anchors.The overall success of the project is reflectedin the numerous engineering and safetyawards for which the project has been nomi-nated. Meanwhile, the successful completionof the anchoring works further advancesStructural Systems’ position as world leadersin the development and execution of ultra-high capacity permanent ground anchors. l

TEAM & TECHNOLOGYOWNERWater Corporation of Western Australia

MAIN CONTRACTORWellington Dam Alliance (WDA) comprisingLeighton Contractors, Structural Systems, Enturaand AECOM in partnership with the WaterCorporation

TECHNOLOGY BBR VT CONA CMG ground


Our first project using panel walltechnology was built near Warsaw – inNowy Dwor Mazowiecki. The viaduct onwhich the reinforced fill technology wasapplied forms part of a scheme to upgradethe E-65 Warsaw to Gdynia railway line. The total surface area of 2,255 m2 con-sisted of four retaining walls – of varyingheights – backing onto two embankments.In one embankment, there was a culvert forpedestrians – its location made this one ofthe most challenging parts of theconstruction project. We participated in a four week designperiod, aimed at optimizing materials andmethodology. Retaining walls were designedas reinforced fill construction withintractable reinforcement, using a IBDiM-compliant panel wall system consisting ofelevated panels and steel zinc-coated wiremesh forming the soil reinforcement, withbackfill placed in successive layers.

The project involved the installation of 606 prefabricated panel units, of which 294 were designed as atypical elements toreflect the slope of the road. The basic1,829 mm x 2,440 mm x 140 mm panelwalls were all produced to concrete bridgesclass C30/37 standards, thus meetingadditional requirements regarding absorb-ability and frost-resistance. We also usedaround 50 t of steel mesh on the project.By choosing this type of prefabricated panelwall, we were able to construct tworetaining walls with a total area of 788 m2

in just four weeks, as well as placing some4,530 m3 of backfill and compaction. The city centre location required wellthought out logistics and organization forhandling materials, as storage on site waspractically impossible. The knowledge andexperience gained from this first implemen-tation will allow us to optimize the designand improve the detailing and assembly onsite. We now look forward to securing stillmore demanding projects and deployingfurther new technological developments. l

The much anticipated completion of their first soil-reinforcedconstruction project was the final step in implementing this technologyand a challenge for engineers, reports BBR Polska engineer Marcin

Harhala who has had much experience of deploying this technology.

TEAM & TECHNOLOGYOWNER PKP-PLK (Polskie KolejePanstwowe – Polskie Linie Kolejowe)

MAIN CONTRACTOR Intercor Sp. z o.o.

TECHNOLOGY Panel wall


ONE GIANT LEAP

REINFORCED SOIL STRUCTURES, POLAND

77CONNÆCT

During manufacture of Ammonium Nitrate –required for explosives in Australia’s miningindustry – the liquid Ammonium Nitrateneeds to be prilled. This process, whichinvolves the chemical being sprayed andcooled to form solid beads, is performedwithin a Prill Skirt. The Prill Skirt for the newplant is approximately 11 m by 6 m in planand is 49.5 m tall. It is designed as a relativelylightweight stainless steel construction to behung from the Prill Tower structure.

After the tower’s structural frame had beencompleted and the lifting equipmentinstalled, the Prill Skirt modules were fed inat ground level. The most critical aspect wasthe necessity for the project team to beworking on the suspended load – performingspecialized stainless steel welding procedures– without compromising safety. Our heavy liftsystem gave the project team the requiredconfidence in safety over-and-above anyalternative lifting system available.

The complete skirt weighed approximately150 t and we utilized four purpose-builtheavy lift hydraulic jacks for the operation. A set of laser distance measurers were usedto monitor the Prill Skirt’s height and levelduring lifting. A typical 5.5 m high lift tookless than four hours to complete.The lifting tendons consisted of 15.2 mm(260 kN MBL) strand and utilized 706 BBRCONA VT CMI anchor heads with wedgeretaining plates for connection to the loadvia a custom-built clevis and pinarrangement. One of our challenges wasdealing with the large load variations due tothe staged lifting process. With the initial liftbeing less than 10 t, only two strands wereengaged upon lift commencement, thusensuring adequate strand loads to providethe necessary wedge draw-in and seatingpressure. As the weight of the lift increased,through the staged addition of modules,additional strands were engaged in the liftingtendons.The complex lifting and Prill Skirtassembly process was completed over aperiod of approximately four months anddeemed a highly successful operation. l


In Central Queensland , Australia, BBR Network Member StructuralSystems was recently engaged to provide heavy lifting servicesutilizing BBR VT CONA CMI technology for the erection of a Prilling

Skirt in the construction of a new Ammonium Nitrate plant.

… THIS WAS A VERY COMPLEXAND CRITICAL PART OF OURPROJECT. IT WAS ESSENTIALTHAT THE ERECTION OF THESKIRT WAS COMPLETEDWITHOUT DELAYS, WITH NOSAFETY CONCERNS AND THATTHE 160 T OF SUSPENDEDMATERIAL WAS FULLYCONTROLLED AT ALL TIMESWITH A LARGE SAFETY FACTORALLOWED FOR ON ALL THELIFTING AND LOWERINGPROCEDURES. ... IT HAS BEEN AVERY SUCCESSFUL OPERATIONFOR THE PROJECT …

JOHN ROBERTS, SUPERINTENDANT,

ALLIANCE JOINT VENTURE

TEAM & TECHNOLOGYOWNER Dyno Nobel Asia Pacific

MAIN CONTRACTOR Alliance Joint Venturebetween United Group Ltd, Bilfinger BergerServices and BGC Contracting, Australia

TECHNOLOGY BBR VT CONA CMI internalHeavy lifting


“

CHEMICAL INDUSTRY

GETS A LIFTPRILL TOWER, MORANBAH, QUEENSLAND, AUSTRALIA

”

78 CONNÆCT

The Al-Wehdah Dam is a roller-compactedconcrete (RCC) dam, designed forconstruction in two stages. The first stagetakes it to 70 m high to a crest elevation of116 m, and the second stage involves raisingit by 30 m to a crest elevation ofapproximately 146 m. The owner required that provisions should beincluded to permit the raising of the dam at alater stage. The dam was constructed usinggrout-enriched RCC (GERCC) facing on boththe upstream and downstream surfaces.A grout curtain cut-off was constructed at theupstream foot of the dam and the abutmentswere extended to a depth sufficient toaccommodate second stage construction. The multi-stage intake structure consisting of a

tower with three intakes at heights of 70 m,80 m and 90 m – along with two concrete-encased 3 m diameter steel conduits and adischarge structure – was constructed in theleft abutment.Our scope, as nominated subcontractor,consisted of the construction of all the CVC

(Conventional Vibrated Concrete), in additionto all necessary upstream and downstreamfacing formwork using climbing formwork atthe upstream face and stepped formwork atthe downstream face and for galleryconstruction.The very tight schedule for constructiondemanded the use of special climbingformwork and scaffolding – plus a 24-hourworking cycle, as the RCC work was carriedout in a continuous 24-hour operation. In just72 hours, we had completed the formworkfor the grouting gallery – approximately 1,170liner meters of three meter high galleries ofwidths varying from 1.5 m to 2.4 m. The PT bar technology helped us gain time andenough strength to deal with the great forcesinduced by the RCC placement and theworking equipment. l

TEAM & TECHNOLOGYOWNER The Ministry of Water and Irrigation,Jordan Valley Authority

MAIN CONTRACTOR Ozaltin ConstructionTrade & Industry Co.

DESIGNER Montgomery Watson Harza (MWH)

CONCRETE WORKS Marwan Alkurdi &Partners Co. Ltd. (Nominated Subcontractor)

TECHNOLOGY PT bar; climbing formwork

BBR NETWORK MEMBER Marwan Alkurdi &Partners Co. Ltd (Jordan)

UK-based BBR Network Member, Structural Systems hasbeen busy assisting with preparations for the 2011 HydePark’s Dextro Energy Triathlon ITU World Championship byconstructing a temporary structure which forms the TataSteel VIP zone. The pavilion is constructed from ‘post-tensioned steel technology’which is an innovative solution and believed to be the first of its kindto be applied to such a temporary structure in the UK.Structural Systems has been working in collaboration with S2 – anAustralian company wihich specializes in the design and constructionof large span steel solutions. The structure comprises a post-tensioned structural steelwork hollow section latticed arch that ispinned at each corner. l

TEAM & TECHNOLOGYOWNER TATA Steel

MAIN CONTRACTOR TATA Steel

DESIGNER S-Squared Corporation Pty Ltd

BBR NETWORK MEMBER Structural Systems (UK) Ltd

TRIATHLON VIP ZONE, LONDON, UK

First for temporary PT structure

BBR Network Member, Marwan Alkurdi & Partners has been working on atechnically demanding construction project for the new Al-Wehdah Dam.The site is in the northern part of the Hashemite Kingdom of Jordan on the

Yarmouk River which forms the border between Jordan and Syria in this location.

AL-WEHDAH DAM, IRBID, JORDAN

Strength against forces

79CONNÆCT

MRR

The earthquakes that struck New Zealand’s‘Garden City’ in 2010 and 2011 have left manyof its buildings in ruins and others in urgent

need of repair. The BBR Network is proud to be help-ing the city get back on its feet – and curious to see

how projects on which it has worked in the past havefared through the earthquakes and the 8,000+ after-shocks that have followed. BBR Contech’s SouthernRegional Manager, Peter Higgins, reports on the workassociated with the response and reconstruction. g

TheChristchurchearthquakes– the BBR Network’s response

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Of those which have survived, a significantpercentage need repair and restoration. BBRContech has been kept busy as a result,working on more than 50 projects in theChristchurch Central Business District (CBD)and beyond. The work has predominantlyfocused on commercial and industrialstructures, as well as infrastructure and awide range of specialist activities have beennecessary.

POST-TENSIONING PERFORMANCEOver the past 10 years, BBR Contech hasdelivered over 30 post-tensioned slab-on-ground projects in Christchurch, ranging insize from 1,500 to 32,000 m2. Thesebuildings are in various locations throughoutthe earthquake-affected region and haveperformed to a very high level.With relatively high compression forcesintegral to the design and a minimum ofjoints, post-tensioned slabs have the ability toresist high loadings and to bridge over areasof local weakness. The performance of theseslabs has not disappointed in Christchurch,with virtually no damage reported. Manywarehouses and storage facilities sufferedfrom collapsed racking, plus damage to otherbuilding elements. However, the post-tensioned floors remained intact andprovided a solid foundation to effect a rapidclean-up – and were ready for service againonce racking and stock was replaced.The slabs have resisted high ground acceler-ations and the self-restoring characteristics ofthe post-tensioning have enabled the floorsto mitigate the effects of the ground motionsand weak subgrades. Other buildings, withconventionally reinforced floor slabs, havesuffered significant damage and the floors arelikely to require replacement. There is also

Most of the damage in Canterbury was caused by three massive quakes– the first on 4 September 2010 (7.1 magnitude on the Richter Scale), thesecond on 22 February 2011 (6.3) and the third on 13 June 2011 (6.3).These – plus further earthquakes in December 2011 and the thousands ofaftershocks – wreaked havoc on the region, with many buildingsdamaged in the first earthquake being utterly destroyed in later ones.The very high ground accelerations, liquefaction and occurrence ofsuccessive earthquake events are unprecedented internationally andbuildings have been subjected to some extreme loading.

BASED ON THE SUPERIORPERFORMANCE OF POST-TENSIONED SLABS, THERE IS AHIGH LEVEL OF INTEREST INUSING POST-TENSIONED SLABS-ON-GROUND FOR NEWBUILDINGS AND TO REPLACEDAMAGED FLOORS

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substantial damage to saw cuts andmovement joints, as a result of lateraldisplacements and pounding.Based on the superior performance of post-

tensioned slabs, there is a high level ofinterest in using post-tensioned slabs-on-ground for new buildings and to replacedamaged floors. A cost premium sometimes

exists for smaller floor areas, but the valueadded by the prospect of minimal businessinterruption is now very much in the mindof building owners and tenants.

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Professor Stefano Pampaninis Associate Professor ofStructural Engineering atCanterbury University,Christchurch. He was invitedto become a member of theExpert Panel of NewZealand’s Department ofBuilding and Housing,reporting to and advising theRoyal Commission of Inquiry(RCI) into the earthquakes

which, in October 2011, released its preliminary observations. Amongother things, the report recommends consideration of newconstruction technologies. For the international construction engineering community, theChristchurch earthquakes delivered no major surprises. There werebuildings designed according to older design standards andtechnology here – as indeed all around the world – that have beenwell-known for their inherently higher seismic vulnerability. Perhapsthe biggest shock was the severity of the 22 February 2011‘aftershock’ – although of smaller magnitude than the main event on 4 September 2010, it was shallower and the level of shaking wasalmost twice what a newly designed building is currently required towithstand. Without the outstanding legacy of Earthquake Engineeringtechniques here in New Zealand, we could have been countingcasualties in thousands, rather than hundreds.There is now a strong need to communicate what we have learntand what the latest technology can offer. Forward-looking dialogueshave been opened with the people and work is underway withgovernment departments to ensure that new construction meetshigher seismic standards. The insurance industry is already playing itscritical part in this process by requiring proof that a building to beinsured incorporates latest damage-resistant technology. The bottom

line is that, in today’s society and in spite of the severity of theearthquake, we cannot afford to have so many buildings damagedbeyond repairability – aside from safety or social considerations,downtime costs are higher than they were even just a couple ofdecades ago. Progress has now delivered better building technology, offering a cost-effective approach. The PRESSS system, consisting of post-tensionedrocking/dissipating precast concrete connections, and its very recentevolution and extension to the timber construction industry, or Pres-Lam system, developed by our team at the University of Canterbury,promote damage-resistant construction capable of sustaining severeearthquake shaking with a minor level of damage and businessinterruption. At present, there are almost 10 PRESSS (concrete) andPres-Lam (timber) buildings either underway or completed in NewZealand – and many feasibility studies and preliminary designs underconsideration. The development and introduction of the Pres-Lamsystem as a viable alternative solution for multi-storey timberbuildings, has sparked some healthy activity within the constructionmarket, previously dominated by just two materials or ‘industrychampions’ – steel and concrete. With a new and very seriouscontender entering the arena, much innovation is underway todemonstrate that they can all offer the same level of safety at acompetitive cost. The reconstruction of Christchurch is an overwhelming challenge –one single industry alone cannot possibly deliver it and this isfostering greater collaboration between industries. It’s often said thatyou can emerge stronger and better from a crisis and that’s hopefullygoing to be true here too – this is our great opportunity to makesomething absolutely brilliant, after such a catastrophic event, andcontribute to the creation of a safer and more beautiful place to live.My congratulations to BBR Contech for being one of the few leadingorganizations which has truly understood the value of investing timeand resources in research and development of new technologiesboth for the design of new buildings and for the retrofitting ofexisting structures. They are well-aligned to benefit from their earlyexperience of using new technologies and materials and I lookforward to our continued working relationship, as we explore yetfurther new damage-resistant design techniques.

On the record: with Professor Stefano Pampanin

Post-tensioned warehouse floors remainedintact, providing a solid base for the clean-up ofcollapsed racking, and businesses were quicklyable to resume trading.

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DAMAGE RESISTANT DESIGNTECHNIQUESIn addition to slabs-on-ground, there is alsogrowing interest in using post-tensionedtechnology in damage resistant designtechniques for multi-storey buildings. PrecastSeismic Structural Systems (PRESSS)technology developed in the United States(see CONNAECT 2008, page 74) has beenutilized on concrete buildings and now thenew Pres-Lam system – which uses post-tensioned timber frames – has been

developed in New Zealand. Several buildingshave already been constructed and furtherprojects are underway. BBR Contech hasprovided post-tensioning for three of theseschemes and is associated with ongoingresearch and development. Theconsiderations and consequences of manymonths of downtime, loss of occupancy andsometimes irreparable level of damage isnow receiving much greater attention frombuilding owners – not just in Christchurch –but all over New Zealand.

REMEDIAL WORKSBBR Contech’s remedial works in the past12 months have covered a wide range ofstructures, from historic buildings to moderntowers, shopping malls, hospitals and bridges.

Demolition underway of the car park of theHotel Grand Chancellor – giving an insight intothe scale of work necessary.

Some, such as the CBD’s Forsyth Barr Towerand Clarendon Tower, may need a double-dose of repairs. After both were damaged inthe September earthquake, our teamundertook crack injection work, injectingepoxy resin, into cracks in floor topping slabs,concrete gravity beams and car park columnsand beams.

Clarendon Tower in the Christchurch CBD,despite repair work following the first quake,may now need demolition.

Instead of concrete, Pres-Lam incorporateslaminated veneer lumber (LVL) anddelivers a similar result to PRESSS by

enabling the building to rock back-and-forthduring an earthquake, then return to anupright position without significant structuraldamage. Pres-Lam offers a number of benefits incomparison with concrete and steelconstruction:u LVL is made from a renewable resource– New Zealand radiata pine.

u Significantly lighter than concrete – largecomponents can be prefabricated thentransported, also requires smaller on-siteequipment and less expensivefoundations.

u Strong and flexible – qualities that holdthe structure together while helping itspring back into place after anearthquake.

u Long term effectiveness is assured – anydamaged sections or beams can berepaired or replaced with relative ease.

u Meeting changing needs – beams andcolumns can be coupled and uncoupledfor alterations, or dismantled altogetherfor use in another construction project.

One such innovative new building – atMassey University’s College of Creative Artsin Wellington – uses the Pres-Lam solution. It will provide flexible studio teaching spaceas well as classrooms and a workshop, green-screen film studio, gallery and multipurposepresentation space. Its lower levels align withthe site contours, while the upper threelevels are supported by a lightweight,naturally ventilated LVL structure comprising15 columns and 16 beams, braced by threeconcrete shear walls. All structural com-ponents have been prefabricated off-site.Project Manager Matt Mumford reports thatBBR Contech’s role was to post-tension thecolumns and beams using tendons

comprising six 12.7 mm strands withcapacities of 1,100 kN. The beam andcolumn tendons are anchored using singlestrand barrel and wedge to large plates ateach end. The concrete shear wall tendonscomprise 1905 anchorages with a capacity of3,500 kN. Unlike the approach used inPRESSS, the strands in the beams andcolumns are greased and sheathed and fullyunbonded, whereas the shear wall tendonshave partial bonding close to the anchorages. This is a highly viable solution that could bethe key to ensuring that buildings – and lives– are saved should the unthinkable everhappen again.

TEAM & TECHNOLOGYOWNER Massey University

MANAGEMENT CONTRACTORArrow International

ARCHITECT Ian Athfield Architects

DESIGNER Dunning Thornton Consultants

TECHNOLOGY BBR CONA internalBBR CONA unbonded


Pres-Lam resists the shakes

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Two shopping malls – The Palms to thenorth-east of Christchurch city and EastgateMall in the east – have had their own shareof trials and tribulations. After the Februaryearthquake, we carried out concrete repairsto the tops and bottoms of a large numberof concrete columns in The Palms retailcentre and adjacent multi-level car parks.This work included forming and pouring withfine aggregate concrete and structuralmortar before confining the columns withcarbon fibre wrap. Further work wasrequired after the June 2011 shake and ThePalms was re-opened in September, whileEastgate opened again in July.

BBR Contech carried out concrete repairs atThe Palms retail centre after the Februaryearthquake.

We have also worked on some importantcommunity infrastructure repairs on hospitalbuildings owned by the Canterbury DistrictHealth Board. The older buildings ofChristchurch Public and Princess Margarethospitals suffered damage to concrete floorsand walls requiring extensive epoxy injectionof cracking. The liquefaction added stress tobasement regions causing ingress of waterand silt. A significant amount ofwaterproofing has been carried out withinjection of polyurethane grouts to stem theflows entering into important service areas.The enormity of earthquake forces can beenobserved in some areas where thickconcrete raft foundations have been pressedupwards by hydraulic forces fromunderneath – causing localised cracking andseparation of construction joints.

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John Hare is a Director of HolmesConsulting Group and has a longassociation with seismic upgrading. He isPresident of the Structural EngineeringSociety New Zealand and currently also aprincipal engineering advisor for theCanterbury Earthquake RecoveryAuthority (CERA).Holmes Consulting and BBR Contech haveworked together on many projects, bothbefore and after the earthquakes. John nowshares with Paul Wymer, BBR Contech CEO,some of the lessons learnt in terms of theperformance of buildings and someinitiatives towards providing greaterearthquake safety for buildings.The learning process is still evolving butsome key observations and considerationsfor the future, so far, are:u Modern buildings on good foundations,constructed in accordance with thebuilding code in force now protectedlives, even when exposed to greatershaking than the code design level.

u Ongoing research and development andthe eventual use of the resultingimproved technology will help to furtherreduce damage in larger earthquakes.

u The seismic design levels for existingbuildings imposed by central and localgovernment are likely to be increased tobetter protect occupants and to providegreater resilience. For new buildings, theexisting load levels may be adequate forlife safety protection, but if owners desirebetter performance, higher load levelsand increased detailing for resilience maybe needed.

u Configure structures, so that they are assymmetrical as possible, to minimizeeccentric loads imposed on someelements.

u A greater emphasis is required on qualitycontrol and inspections duringconstruction to ensure that the intendedmethods of construction are achieved.

u Insurance and reinsurance considerationsare likely to drive a greater level ofattention to seismic resistance. Olderbuildings and those that are deemedearthquake-prone may becomeuninsurable or could be subject tospecial exclusions and high premiums.

Many of these lessons and initiatives toprovide greater earthquake safety willinevitably result in extra costs for buildingowners and tenants. The question of howthese costs balance out against the riskappetite for the general public andGovernment imposed design levels remainsto be seen. However, with the Christchurchrebuild expected to cost in the order ofNZ$15 billion, there will be a strongbusiness case to support consideration ofsome additional cost at the time ofconstruction or retrofitting. And included inthis business case will surely be a very closeanalysis of the insurance position.

Learning lessons and sharing initiatives

In contrast, the new Christchurch Women’sHospital opened in 2005 is the first building

in the South Island to use base isolationtechnology and it performed exactly asintended. This 10 storey state-of-the-artbuilding has more than 20,000 m2 of floorarea and was designed to withstandChristchurch’s largest predictable earthquake.The building foundation includes fiveunbonded multi-strand tie-down tendonsanchored beneath the raft foundation –three with BBR CONA 4205 and two withBBR CONA 1205. These anchors work intandem with the base isolation bearings toprovide the restraining force against upliftduring a seismic event g

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While nearly every building in the ChristchurchArts Centre complex is in need of extensiverepair, the Old Arts School remains largelyuntouched. The FRP strengthening work weunder-took in 2008 contributed to this resilience.But the Great Hall was not so lucky – after theJune 2011 earthquake, we were engaged in aproject to hold it together until a permanentrepair solution can be found. This work involvedusing five cranes to install strand and bar tendonsthrough temporary structural steel frames at gablewall ends.

Strand and bar tendons installed through temporarystructural steel frames at gable wall ends must holdthe Great Hall together until a permanent repairsolution can be found.

Another, more recent, FRP strengthening projecthas also delivered results. Just five days before theSeptember earthquake, we completedstrengthening 23 circular columns at theUniversity of Canterbury’s Student ServicesBuilding. This involved applying two layers of glassfibre wrap in the top and bottom 600 mm of thecolumns. Our post-earthquake inspectionrevealed that the columns remained intact andnew cracks had appeared behind the glass fibrewhere the additional confinement had resistedthe earthquake loading – exactly as intended.

SUPPORTING RESEARCHGiven its involvement in these andmany more earthquake-relatedprojects, we are delighted to beparticipating in a six-year Universityof Canterbury earthquakeengineering research study with thetheme of ‘Retrofit Solutions for NewZealand Multi-Storey Buildings’. The research team has built a three-storey pre-1970s reinforced

concrete model building – to 40% scale – and hasbeen testing it on the ‘shake table’ at theUniversity’s Structures Laboratory. They areinvestigating the structural dynamics of the buildingbefore and after a rehabilitation or retrofitintervention, with the aim of upgrading itsperformance when subject to the groundmovements produced by earthquakes. The team has recently studied the response of thebuilding due to ground motions recorded in theSeptember 2010 Christchurch earthquake and

BBR projects – how did they fare?Strengthening work carried out earlier by BBR Contech contributed to the resilience of Christchurch Arts Centre’s Old Arts School.

Just five days before the September earthquake, BBR completed the strengthening of 23circular columns at the University of Canterbury’s Student Services Building.

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Chile’s 8.8 magnitude earthquake in February2010. The next steps involve observing itsresponse to the same conditions when we haverepaired and rehabilitated it with GFRP (glass-fibre-reinforced polymer) – a solution that is neitherinvasive, nor expensive. In the light of what hasbeen happening in Christchurch, there will bemuch attention focused on the outcome.

A LONG-TERM OUTLOOKThe Canterbury rebuilding programme has justbegun. We have provided estimates for a largenumber of projects – with approvals subject to theresolution of insurance issues and landdesignations.The continuing aftershocks mean that nothing iscertain. While a number of CBD buildingsinvestigated for repair have since been demolished,about 1,200 others remain standing awaitingdecisions on their fate – and may eventually bedeemed economic to repair. Whatever theoutcome, the nature of the reconstruction willchange the face of Christchurch and BBR Contechstands ready to help – with repair andstrengthening or new build technology – andalways with an eye to protecting, preserving andfuture-proofing Christchurch’s built environmentfor many years to come. l

Originally built in 1981, the overpass hadthree traffic lanes, plus two pedestrianwalkways, on its 15.2 m structure.Reconstruction was completed in twophases. The first was between axis OIand axis 7, where the superstructurewas widened and the second, betweenaxis 7 and axis OD, where it wasnecessary to demolish thesuperstructure and build a new one. In the new layout, the overpass liesbetween two circular junctions, with theSemedela junction sitting partially on thestructure.The new traffic solution requires four3.25 m wide traffic lanes. As there is apedestrian underpass near the structure,it was decided that a pedestrian lanewas not necessary. This made it possibleto meet new traffic requirements withstrengthening and minimal widening ofthe superstructure between axis OI andaxis 7.For the second phase, there was 1.2 mheight difference between the old and

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new structure and this part of theoverpass also widens in a funnel shape.The latter was the reason for deciding todemolish the old superstructure and builda new one.The superstructure was executed as acontinuous slab with cantilevers on bothsides and longitudinal post-tensioning with51 BBR VT CONA CMI 1506 tendons.While the width of the structure varies, itsthickness of 1.05 m is constant. Lack ofaccess meant that tendons had to bestressed from one side to a force of 2,900 kN each – resulting in a total forceof almost 150 MN. l

An existing overpass has been rebuilt during the constructionof the new H5 Koper to Izola Expressway in Slovenia.Kresimir Bogadi of BBR Adria presents a brief insight into

the project.

TEAM & TECHNOLOGYOWNER DARS d.d.

MAIN CONTRACTOR Kraski Zidar d.o.o.

DESIGNER GRADIS Biro Za ProjektiranjeMaribor d.o.o.

TECHNOLOGYBBR VT CONA CMI internal

BBR NETWORK MEMBERBBR Adria d.o.o. (Croatia)

SEMEDELA OVERPASS, KOPER, SLOVENIA

Complex reconstruction

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Having already completed a majorwharf repair project at Auckland’sDowntown Ferry Terminal, BBRContech was familiar with thewaterfront environment. So thecompany was pleased to take on thetask of repairing the substructure ofQueens Wharf – one project amongmany to prepare it for its role as thevenue for Rugby World Cup 2011’s‘Fanzone, Festival and Showcase’ events. Thousands descended on the wharf towatch the games on big screens, enjoyfree concerts by top Kiwi bands andexperience displays of New Zealand’screativity, innovation and ingenuity. Keyattractions included ‘The Cloud’, apurpose-built structure capable ofholding more than 6,000 people; the‘ANZ Dome’, which offered a host ofinteractive experiences; and the GiantRugby Ball, which provided an audio-visual experience of New Zealand andits landscape, culture and tourismattractions.

Built of reinforced concrete andcompleted in 1913, Queens Wharf is animportant part of Auckland’s social,industrial and engineering heritage. It isthe second oldest wharf structure lefton the waterfront – and originallydeveloped as a key hub for NewZealand’s burgeoning import andexport industries. One hundred years after it was built,the wharf was naturally exhibiting signsof deterioration. BBR Contech’s job wasto make it structurally sound byremoving and reinstating 185 m3 ofconcrete and replacing much of thereinforcing bar – essentially two-thirdsof the wharf ’s substructure. Thedefective concrete was removed using‘hydro-demolition’, applying high-pressure water to deliver an excellentbonding surface for repairs whileminimising noise in the inner cityenvironment.The work was completed four weeksahead of schedule, the team having

overcome all the challenges of workingwith the tides, managing the risks ofoperating in such a public location,dovetailing the work schedule withother projects happening on the wharf,and ensuring all the debris was disposedof responsibly. BBR Contech alsocompleted a separate contract,undertaking repairs to the wharf deckwhile ensuring that historic featuressuch as old railway lines were preservedand restored.The client was delighted with theresults.“What impressed me most was theconsistency with which BBR Contechperformed,” says Mark Fraser, ProjectLeader Queens Wharf for WaterfrontAuckland. ”The team delivered exactlyas they said they would, but ahead oftime and with a larger scope than weoriginally set out to achieve, all thewhile working around and with twoother contractors on site. Deliveringpossibly the highest-volume repairproject in New Zealand and in such ashort timeframe made for a veryimpressive performance.”

Speaking of impressive performances,the New Zealand All Blacks completedthe tournament unbeaten and went onto meet France in the final on 23rdOctober 2011 – and winning in a veryclose and exciting match. After winningthe inaugural World Cup competition in1987, the All Blacks had endured a longwait before they could again hold theWilliam Webb Ellis Trophy aloft tocrown them as 2011 Rugby WorldChampions, much to the relief of thewhole nation – the so-called ‘stadium offour million people’. l

Between 9 September and 23 October 2011, New Zealandbecame the centre of the rugby universe, with 20 teamsvying for the title of Rugby World Cup champion. In

preparation for this huge international event, Auckland’swaterfront area – designated ‘Party Central’ – underwent someredevelopment to deal with the large influx of fans and BBRContech was associated with a number of projects. BBR Contech’sNorthern Regional Manager, Keith Snow and Project Manager,Mark Kurtovich outline the work associated with the repair andstrengthening of Queens Wharf in preparation for the event.

TEAM & TECHNOLOGYOWNER Waterfront Auckland

MAIN CONTRACTOR BBR Contech

DESIGNER Beca Infrastructure

TECHNOLOGY MRR range


Repairs for the rugbyQUEENS WHARF, AUCKLAND, NEW ZEALAND

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Supplying the demands of energy hungry populations is a constantbattle for governments, scientists and businesses. Increasinglyenvironmentally-friendly – or ‘sustainable’ – solutions are required from

the construction industry, while the practicalities and associated costs mustbe weighed by infrastructure owners. With all these factors in mind, there aresome compelling advantages for choosing BBR technology. We examinethree sectors – hydroelectric, nuclear and wind energy – where the expertiseof the BBR Network has made a significant and sustained contribution. g

Electrifyingperformance LA

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INFRASTRUCTURE FOR ENERGY

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Lean,greenyet strongAs long as the human race inhabits this planet,

it will need energy to survive. The challengenow is for us to be able to satisfy our energy

needs in a sustainable and economically viable way.Use of post-tensioning promotes a sustainableapproach and reduces concrete volumes used, thusdelivers a lower carbon footprint. The BBR VT CONACMX range is particularly lightweight, very compactand further reduces cross-sectional areas of concretestructures due to the small centre spacingrequirement between anchorages. In addition,recycled concrete can be used effectively with CONACMX post-tensioning as the tendons can be stressedat comparatively low concrete strengths.

The constant development of BBR technology, driven by customersthrough contact with the BBR Network, means that we can supplylean yet strong solutions for all types of structure. Our solutions arelean because you only use the amount of material you actually needwhile achieving the same structural strength. In essence, with ourCONA CMX technology, we have engineered out the surplus.As you will have seen, in Consuming passion for LNG on pages 49-53,the use of BBR post-tensioning for LNG tank construction offers asaving in both time and materials, while creating energy infrastructurethat is eminently maintainable. Now, we look at three further types ofenergy installation where BBR technology and know-how plays acrucial role.

Dams are unique amongstructures because of their hugesize and the massive amount of

water or other liquids they retain – andthe vast scale of human, ecological andeconomic losses their failure wouldbring. They are expected to age anddeteriorate over time due to geologicaland chemical factors, thus programs ofsurveillance and maintenance – usingcontinually advancing technology – areimplemented to ensure their continuedsafe operation.

BBR ground anchoring technology hasbeen used in dam construction andstrengthening projects for over 60 years.The first BBR prestressed ground anchorswere used in 1951 to anchor the walls ofthe underground machine room for theMaggia Hydroelectric Power Station inVerbano, Switzerland. The followingprojects are milestones in the evolution inthe use of BBR technology andtechniques on the international scene fordam strengthening and stabilization andrepresent just a small number of suchprojects carried out by the BBR Network.

STABILIZING INTAKEIn the early 1960s, BBRV rock anchorswere used to stabilize intake sections ofthe Wanapum Dam in Washington State,USA, allowing for later construction ofthe power house substructure. Thirteenanchors were placed in each intake andholes were drilled to a maximum of 80 ft into the rock foundation. Afterstructural concrete had been placed andattained the required strength, theanchor assemblies were lowered intothe drilled holes and the bottom 30 ftgrouted.

HYDROELECTRICITY

Harnessing hydro power

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MAJOR REHABILITATION After rains, brought by Hurricane Agnesin 1972, raised the water in thereservoir to 2.5 ft above its normallevel, the decision was taken to upgradethe 50-year old Conowingo Dam inMaryland, USA. This initiated what wasthen thought to be the biggest damrehabilitation project using post-tensioned anchorages in the world. Theproject involved drilling through some200 ft of concrete and bedrock toinstall 1,100 t of prestressing steel in theform of 537 BBRV rock anchors. Today,the dam provides feedwater forhydroelectric power generation, coolingwater for a nuclear power station andwater for public supply.

GROWING STABILITYIn 1985, Australia’s Chichester Dam, onthe Hunter River, was fitted with BBRVrock anchors to increase its stability andheight. The anchors, weighing up to threetons each, were installed using a specialdevice – running on the crest of the dam– which was equipped with pulling andbreaking winches. The anchors wererequired to have double corrosionprotection, facilities for force monitoringat any time and to be restressable duringthe lifespan of the dam.

UPGRADING & SECURINGThe upgrading project in the early1990s at Waitakere Dam, nearAuckland, New Zealand, featured the

installation of 55 vertical BBR CONArock anchors with lengths of up to 60 m. The anchors have the facility forcontinuous load monitoring andrestressing. 260 BBRV tendons passthrough the dam to stress together thesections of the original 1910 dam andthe dam extension built in 1928. TwoBBRV tendons were provided for eachvertical rock anchor to resist burstingstresses.

WORLD RECORD CAPACITYANCHORSThe existing ground anchors atCatagunya Dam had reached the end oftheir service life and were replacedusing 92 BBR VT CONA CMG tendonsbut, with reduced availability of anchorlocations, even higher capacity wassought. This led to the adoption of 91–strand tendons using 15.7 mm diameterstrand – and setting new world recordsfor permanent ground anchors, with anMBL of 25,389 kN, test load of 19,415 kN (1,980 t) and lock-off load of17,772 kN (1,812 t). Since this projectwas completed in 2010, similar ultrahigh capacity anchors have also beeninstalled at Wellington Dam in WesternAustralia, see pages 76 and 77. l

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BBR has over 60 years’ experience in the design and application ofpost-tensioning products. Within the nuclear industry, the focus ofthe BBR Network is on safety and maintenance to extend the safe

operating life of existing plants. Our leading edge technology and know-how has been applied to 65 nuclear facilities in many countries.

Nuclear reactors have a nominal design lifeof around 30 years, however, this may beextended by further investment in reactormaintenance upgrades. The Ringhals NuclearPower Station, in Sweden, is one plant wheresuch investment is currently underway, withthe help of the BBR Network.

THE RINGHALS STORYSweden has a total of ten nuclear reactors –four at Ringhals, three at Oskarshamn and

three at Forsmark – and all feature BBRtechnology. Today, nearly 50% of Sweden’selectrical energy is produced by nuclearpower plants.Ringhals, on the west coast some 60 kmsouth of Gothenburg, is the largest powerplant in Scandinavia. It has four reactors –number 1 is a boiling water reactor andnumbers 2, 3 and 4 are pressurized waterreactors. In a normal year, Ringhals generatessome 28 billion kilowatt hours of electricity –about one fifth of Sweden’s total electricalenergy consumption. The Swedish government decided not toshut down the Ringhals plant as originallyplanned, but to upgrade it instead. Now,discussions are underway about replacing theold reactors when the time comes, ratherthan building new ones.

NUCLEAR REACTOR UPGRADINGTommy Lindstrand of Swedish BBR NetworkMember Spännteknik AB explains thatRinghals 1 is prestressed with 55 6 mmdiameter, cement-grouted BBRV tendons,while Ringhals 2, 3, and 4 are pre-stressedwith 139 6 mm diameter BBRV tendons andgrouted with a grease/petrolate type nucleargrade casing filler. The upgrading of Ringhals 4 includedreplacing three steam generators and onecondensator to increase safety and securefuture electricity production. We had carried

NUCLEAR POWER

Realizing longevity & safety

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out very similar work on an earlier occasionfor both Ringhals 2 and 3.

TRANSFER OPENINGThe work required a transfer opening in thesecondary containment wall of 6 m by 8 m.The 1,200 mm thick wall has a 20 mm steellining at approximately 1,000 mm from theouter surface.

A steam generator is about 21 m long andweighs nearly 334 t. Lifting operations,performed on the outside, were assisted by a660 t crane. A slide way was installed in theopening to allow removal of the oldequipment and insertion of the new kit intothe reactor building.

BALANCING CONTAINMENTOur job was to remove the tendons crossingthe required opening – and, to keep thecontainment in balance, we de-stressed manyother tendons too.Our scope of work included:u Training program in 2010 – connectingand testing of ducts in the opening

u Training program in 2011 – de-stressingand stressing of tendons

u De-stressing, removal, storage, installationand stressing of nine vertical and 20 horizontal tendons

u De-stressing and stressing of 56 horizontal tendons

u Grease grouting of 85 tendonsu Delivery, installation and testing of smoothducts for tendons in the opening

u Tent, including dehumidification, forstorage of tendons

u Work planning and documentationu Necessary courses and medicalexamination

u Accommodation for our personnel

At times, we had to work around-the-clockand this required a team of 24 people.With the grouting of the last tendons on 20 September 2011, our work here on thismajor project was finished. All documentsare now approved – and both the client andindeed our own team are very satisfied withthe job which was performed exactlyaccording to the plan. l

LANDMARK STRUCTURES

TEAM & TECHNOLOGYOWNER Vattenfall

MAIN CONTRACTOR AREVA NP GmbH

LIFTING & CONCRETING SUBCONTRACTORNCC

TECHNOLOGY BBRV wire

BBR NETWORK MEMBERSpännteknik AB (Sweden)

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A total of 84,074 MW is now installed in theEuropean Union, a growth of 12.2% on theprevious year. Germany remains the EUcountry with the largest installed capacity,followed by Spain, France, the UK and Italy.The European offshore wind power marketexperienced a massive increase of 51%during 2010.Since the end of the 1990s, the BBRNetwork has been involved in both researchand development, as well as the constructionof wind towers – often in harsh, inhospitableenvironments. So far, BBR NetworkMembers have been contracted for over 12 wind park projects and prototypes.

WIND TOWER CONSTRUCTIONBasically, three types of construction arecommon for the wind towers – steel,concrete and a hybrid mixed version.Currently, the hybrid construction methodseems to be the most economical for high

towers which require thicker walls and towerdiameters in the foot. Post-tensionedconcrete plays an important role in realizingthe full potential of wind energy. Concretetower solutions are adaptable and durable

and offer long life performance withminimum maintenance. The use of precast orin-situ PT concrete, rather than steel, in theconstruction of windfarms offers severaladvantages to owners and operators:u Reduced maintenance costs and long-lifeperformance – through comparativedurability of concrete over steel.

u Up to 15% higher energy production – PTconcrete pylons can be 30-40 m higher.

u Lower transportation costs – casting isnot highly specialized and can be carriedout near the site.

u Design and construction flexibility –versatility of concrete enables designsolutions with no restrictions on height orsize.

u Dynamic performance – PT concrete hasinherently high damping properties andcan deliver fatigue resistance solutionswith less noise emissions.

Taller wind towers need greater structuralstrength and stiffness to carry both theincreased turbine weight and bending forcesfrom wind action on the rotors and thetower and also to avoid damaging resonance.

WIND ENERGY

Chasing the wind

Despite tough economic conditions, global wind powercapacity rose to 197 GW – a 24.1% increase over the previousyear. The outlook for 2011 is more optimistic, with overall

investment predicted to reach €70.4 billion (US$96 billion) – andlikely to translate into actual projects during the next two years.

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Key issues are the minimization of materialcontent and structural weight and reductionof construction time. In-situ slipformconstruction overcomes the problems oftransporting large tower rings/sections andneed for large cranes for erection.The ability to prestress concrete means thatindividual wind tower structures can betailored to provide optimal levels of stiffnessand dynamic performance using post-tensioned tendons.Ducts can be incorporated into both precastconcrete units and in-situ concrete – eitherlocated within pylon walls or externally onthe inner wall of the pylon structure. Thisfacilitates thin, lightweight wall constructionwith simple access for inspection and futurecapacity upgrades. A combination of internaland external tendons can be consideredwhereby, for instance, external tendonsstabilize the tower from the base up to adefined stage and are anchored in a corbel.Internal tendons are stressed at full heightfrom the top corbel to the base segment.The move towards taller wind towers istipping the balance towards PT concretedesign solutions with their many advantages.BBR VT CONA CMX products – groundanchors, band systems, internal and externalpost-tensioning – are well-suited to theconstruction of precast elements or in-situconcrete method used for windfarms. Withthe know-how of BBR Network Members,concrete pylons could reach heights ofover120 m!

TESTING TIMESRecently, Vorspann-Technik – the GermanBBR Network Member – constructed two130 m high prototype wind towers using

CONA CMB tendons at a test field inBremerhaven. Meanwhile in Hamburg, theybuilt a further two towers using CONACMB technology – these towers areapproaching 140 m high and have rotorscovering an area larger than a football pitch!

CHILLY ARCTIC WINDS The team from BBR Network Member, KB Spennteknikk in Norway, faced an arcticclimate and persistently strong winds toprovide foundations for 17 windmills fortheir client Statkraft. The Kjøllefjord WindProject is located 74° North, on MountGartefjell – 230-300 m above sea level – inthe municipality of Lebesby in Finnmark,Norway. Foundations for the windmillsconsisted of 136 CONA Multi 1906 rockanchors – eight anchors per windmill. The

expected average annual output of the windfarm – which opened in October 2006 – isin the region of 150 GWh, equal to theconsumption of around 7,500 households.

STORMY WATERSA wind farm has been built in Lake Vänern –covering an area of 5,655 km2, it is the thirdlargest lake in Europe. Spännteknik, the BBRNetwork Member in Sweden played a keyrole in delivering the Vindpark Vänern windenergy project. The round six meterdiameter foundations had been prefabricatedin one meter high sections with recesses forthe tendons. Each foundation was anchoredby 16 BBR CONA 1906 rock anchors – witha length of 25-28 m, depending on the waterdepth and with the help of divers.

TECHNOLOGY FOR THE FUTUREAs well as awesome dam structures, timelynuclear power services and breathtakingwind energy projects, BBR ground anchorshave also been applied, as reported inCONNAECT 2008, to strengthen bases ofelectricity transmission tower bases in NewZealand’s South Island. It is clear that theBBR Network has both the technology andthe expertise to support the many anddiverse needs of the energy sector well intothe future! l

LANDMARK STRUCTURES

94 CONNÆCTCONNÆCT94 CONNÆCT

SWITZERLANDBBR VT International LtdBahnstrasse 238603 Schwerzenbach (ZH)

Tel +41 44 806 80 60Fax +41 44 806 80 50

[email protected]

EASTERN CANADACanadian bbr Inc.3450 Midland Ave.ScarboroughOntario M1V 4V4

Tel +1 416 291 1618Fax +1 416 291 9960

[email protected]

AUSTRIAKB Vorspann-Technik GmbHWeitwörth 255151 Nussdorf a.H.

Tel +43 6272 40790Fax +43 6272 4079040

[email protected]

BELGIUMsee Netherlands

BOSNIA/HERZEGOVINAsee Croatia

BULGARIAsee Spain

CROATIABBR Adria d.o.o.Kalinovica 310000 Zagreb

Tel +385 1 3839 220Fax +385 1 3839 243

[email protected]

CZECH REPUBLICsee Austria

DENMARKsee Norway

ESTONIAsee Austria

FINLANDsee Norway

FRANCEETIC S.A.48, rue Albert Joly78 000 Versailles

Tel +33 1 39 50 11 20Fax +33 1 39 50 11 03

[email protected]

GERMANYKB Vorspann-Technik GmbHFürstenrieder Strasse 27581377 München

Tel +49 89 72 44 969-0Fax +49 89 72 44 969-12

[email protected]

HUNGARYsee Austria

IRELANDsee United Kingdom

LATVIAsee Austria

LITHUANIAsee Austria

MONTENEGROsee Croatia

NETHERLANDSSpanstaal B.V.Koningsweg 283762 EC SoestPost Address: PO Box 3863760 AJ Soest

Tel +31 35 603 80 50Fax +31 35 603 29 02

[email protected]

EUROPEHEADQUARTERS

AMERICAS

Additional BBR technology licenses have been granted in Europe, AsiaPacific and America – for moreinformation, please contact the BBRHeadquarters.

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BBR DIRECTORY

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NORWAYKB Spennteknikk ASSiva Industrial EstateN. Strandsveg 19-21Postboks 12132206 Kongsvinger

Tel +47 62 81 00 30Fax +47 62 81 00 55

[email protected]

POLAND(Head Office)BBR Polska Sp. z o.o.ul. Annopol 1403-236 Warszawa

Tel +48 22 811 50 53Fax +48 22 811 50 53 55

[email protected]

BBR Polska Sp. z o.o.ul. Tarnogorska 214a44-105 Gliwice

Tel +48 32 331 47 98Fax +48 32 330 24 11

[email protected]

PORTUGALsee Spain

ROMANIAsee Spain

RUSSIAsee Austria

SERBIAsee Croatia

SLOVAKIAsee Austria

SLOVENIAsee Croatia

SPAINBBR Pretensadosy Técnicas Especiales, S.L.Antigua Carretera N-IIIKm. 31, 15028500 Arganda del Rey, Madrid

Tel +34 91 876 09 00Fax +34 91 876 09 01

[email protected]

SWEDENSpännteknik ABSjöängsvägen 7192 72 Sollentuna

Tel +46 8 510 678 10Fax +46 8 510 678 19

[email protected]

UKRAINEsee Poland

UNITED KINGDOMStructural Systems (UK) Ltd12 Collett WayGreat Western Industrial EstateSouthallMiddlesexUB2 4SE

Tel +44 20 8843 6500Fax +44 20 8843 6509

[email protected]

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BAHRAINsee United Arab Emirates

IRAQSpecialized Prestressing CoKarrada, Dist. 901, St. 1, Bldg. 16Office No. 10Baghdad

Tel +964 79 016 612 56

[email protected]

JORDANMarwan Alkurdi & PartnersCo. LtdPO Box 506Amman 11821

Tel +962 6 581 9489Fax +962 6 581 9488

[email protected]

OMANsee United Arab Emirates

QATARsee United Arab Emirates

KINGDOM OFSAUDI ARABIAHuta-Hegerfeld Saudia LtdBBR Prestressing DivisionPrince Sultan St. Lotus BuildingPO Box 1830Jeddah

Tel +966 2 662 3205Fax +966 2 683 1838

[email protected]

SYRIAsee Jordan

SOUTH AFRICAStructural Systems (Africa)Block B, 60 Civin DrivePellmeadow Office ParkBedfordview, Johannesburg 2007Tel +27 11 409 6700Fax +27 86 616 7482

[email protected]

UNITED ARAB EMIRATESNASA Structural Systems LLC(Head Office)Office 603PO Box 28987Dubai

Tel +971 4 2948 974Fax +971 4 2948 984

[email protected]

Structural Systems Middle East LLCOffice M-01, Mezzanine FloorBuilding Ref C-57Al Muroor RoadPO Box 126740Abu Dhabi

Tel +971 2 6438 220Fax +971 2 6438 221

[email protected]

Emirates & Australia Const.Systems LLCOffice 112Hatem Kamal Farah BuildingBeirut StreetPO Box 62174Sharjah

Tel +971 6 5437 490Fax +971 6 5437 491

[email protected]

INDIABBR (India) Pvt LtdNo. 318, 15th Cross, 6th MainSadashivanagarBangalore – 560 080

Tel +91 80 4025 0000Fax +91 80 4025 0001

JAPANJapan BBR Bureauc/o P.S. Mitsubishi ConstructionCo. LtdHarumi Center Bldg. 3F2-5-24 Chuo-kuTokyo

Tel +81 3 6385 8021Fax +81 3 3536 6937

[email protected]

MALAYSIABBR Construction Systems (M)Sdn BhdNo. 17, Jalan PJS 11/2Subang IndahBandar Sunway46150 Subang JayaSelangor Darul Ehsan

Tel +60 3 5636 3270Fax +60 3 5636 3285

[email protected]

ASIA PACIFICMIDDLE EAST

AFRICA

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PHILIPPINESBBR Philippines CorporationSuite 502, 7 East Capitol BuildingNo.7 East Capitol DriveBarangay KapitolyoPasig City Metro Manila 1603

Tel +632 638 7261Fax +632 638 7260

[email protected]

SINGAPOREBBR Construction SystemsPte LtdBBR Building50 Changi South Street ISingapore 486126Republic of Singapore

Tel +65 6546 2280Fax +65 6546 2268

[email protected]

THAILANDSiam-BBR Co Ltd942/137.1 5th FloorCharn Issara TowerRama 4 RoadKwaeng Suriwongse, Bangrak10500 Bangkok

Tel +66 2 237 6164-6Fax +66 2 237 6167

[email protected]

VIETNAMsee Singapore

AUSTRALIAStructural Systems (Northern)Pty Ltd20 Hilly StreetMortlakeNew South Wales 2137

Tel +61 2 8767 6200Fax +61 2 8767 6299

[email protected]

Structural Systems (Northern)Pty LtdUnit 1/12 Commerce CircuitYatalaQueensland 4207

Tel +61 7 3442 3500Fax +61 7 3442 3555

[email protected]

Structural Systems (Southern)Pty LtdPO Box 1303112 Munro StreetSouth MelbourneVictoria 3205

Tel +61 3 9296 8100Fax +61 3 9646 7133

[email protected]

Structural Systems (Western)Pty LtdPO Box 4050Victoria ParkWestern Australia 69793 Craig StBurswoodWestern Australia 6100

Tel +61 8 9267 5400Fax +61 8 9267 5499

[email protected]

FIJIsee New Zealand

NEW ZEALANDBBR Contech6 Neil Park Drive, East TamakiPO Box 51-391PakurangaAuckland 2140

Tel +64 9 274 9259Fax +64 9 274 5258

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BBR Contech38 Waione Street, PetonePO Box 30-854Lower HuttWellington 5040

Tel +64 4 569 1167Fax +64 4 569 4269

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BBR Contech7A Birmingham DriveMiddletonPO Box 8939RiccartonChristchurch 8440

Tel +64 3 339 0426Fax +64 3 339 0526

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BBR DIRECTORY

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