Comparison between uniaxial and biaxial test methods ... · The slope of the “Graben ... achieve minimum truss diameters. The horizontal upper girder cantilevers at both ends, in

Comparison between uniaxial and biaxial test methods

MECHANICAL PROPERTIES OF ETFE FOILS

Anticlastic minimal surfaces as elements in architecture

SOFT.SPACES

N E W S L E T T E R O F T H E E U R O P E A N B A S E D N E T W O R K F O R T H E D E S I G N A N D R E A L I S A T I O N O F T E N S I L E S T R U C T U R E S

NEWSLETTER NR. 21SEPTEMBER 2011PUBLISHED TWICE A YEARPRICE €15 (POST INCL)www.tensinet.com

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TENSINEWS NR. 21 – SEPTEMBER 20112

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Saint-Gobain www.sheerfill.com

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technet GmbHwww.technet-gmbh.com

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Editorial BoardJohn Chilton, Evi Corne, Peter Gosling, Marijke Mollaert, Javier Tejera

CoordinationMarijke Mollaert, phone: +32 2 629 28 45, [email protected]

Address Vrije Uni ver siteit Brussel (VUB), Dept. of Architectural Engineering,Pleinlaan 2, 1050 Brus sels, Belgium fax: +32 2 629 28 41

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RESEARCH

10 SOFT.SPACES

PA G E

6 Mechanical properties of ETFE foils

8 S(P)EEDKITS

PA G E

20 Tensile Structures Montevideo 2011

PA G E

4 France OPEN-AIR THEATER 1800m² suspended structure

4 Germany TEMPORARY ROOF STRUCTURE

9 Ukraine OLYMPIC STADIUM Reconstruction

16 China HOME OF THE FUTURE A showcase for future living

16 Argentina LA PLATA STADIUM High-light transmission membranes

17 Germany MEMBRANE ROOF Rhein-Galerie

18 Malta STONE-AGE TEMPLE Membrane roofs shelter

23 Spain TEXTILE WRAP A sustainable construction

n°21

REPORT

PA G E

19 LITERATURE

24 INTERNATIONAL "TEXTILE STRUCTURE FOR NEW BUILDING 2011” COMPETITION FOR STUDENTS AT TECHTEXTIL

TENSINEWS NR. 21 – SEPTEMBER 2011 3

Edito

Forthcoming Events International symposium IABSE-IASS 2011 London,UK 20-23/09/2011 ● International conference on Structural Membranes 2011Barcelona, Spain 05-07/10/2011 http://congress.cimne.com/membranes2011/frontal/Dates.asp ● 1st international Textile Archi tecture Seminar Universidad de Castilla-La Mancha,Toledo, Spain 26-28/10/2011 ● second international conference on flexibleformwork icff 2012 Bath, UK 27 - 29/06/2012 www.icff2012.co.uk

Forthcoming MeetingsTensiNet meetings in Barcelona, Spain Thursday 4/10/2011 16:30 - 17:00 Welcome17:00 - 18:00 Partner Meeting (2/2011)18:00 - 19:00 Annual General Meeting19:00 - 21:00 Working Group Meetings "Specifications" (Marijke Mollaert),

"Analysis & Materials" (Ben Bridgens) and "ETFE" (Rogier Houtman)

Location: Technical University of Catalonia (UPC), Master Room, Building A3, Campus Nord, Jordi Girona 1-3, Barcelona, Spain

CEN/TC250 WG5 _ core group meeting in Paris, FranceWednesday 02/11/2011 10:00 - 16:00Core Group Meeting

Location: SFEC, 3rd floor, 65 Rue Prony, Paris, France

CALLCALLfor Participants for

TensiNet Working Group onPneumatic Structures

Pneumatic Structures are increasingly being considered for a variety ofapplications in the built environment, from stadium roofs to bridges, andfrom permanent structures to deployable enclosures. The design, analysisand specification of these structures is often treated differently bydifferent consultants in different countries, with occasional reliance uponqualitative and empirical experience, or applications from other industries.

TensiNet is launching a working group on Pneumatic Structures toconsolidate the current best practise in this specialist field. It is envisagedthat this working group will focus on analysis techniques, designprocesses, applicable standards and technical references, materialityoptions, and construction practicalities. Reference will be made to theexisting working groups on ETFE and Analysis & Materials withoutduplicating their findings, of course. The aims, scope and membership of the working group will be discussedat the start-up meeting to follow after the Annual General Meeting ofTensiNet in Barcelona on 4th October 2011. Any interested parties whowould like to participate should contact the leader of the working group,Matthew Birchall, at [email protected]

Tensinews observes the current trend of expandingthe use of technical membranes and foils in architecturalprojects. The variation in available materials is increasing, with respect to the appearance as well as the (structural)behaviour. The field of application is widening; more delicate,creative and intriguing projects are being built and morearchitects explore the possibilities of the technology of tensilesurface structures, e.g. textile sustainable wraps, a large span stadium cover or a heritage shelter to protect anarchaeological temple. A holistic approach is the way to go for these designs.

Numerous workshops, symposia - like the 4th Latin AmericanSymposium on Tensile Structures in Montevideo - andconferences act as forums to discuss and disseminate the state of the art. The next TensiNet Symposium is plannedfor 2013. The younger generation is stimulated to hand in their student-projects at the bi-annual International "TextileStructure for New Building 2011” Competition at Techtextil.

There is also an increase in research projects to deepen thecurrent knowledge, like testing and analysing the materialproperties of coated fabrics and foils, the study of deployableS(P)PEEDKITS for disaster relief or the exploration ofanticlastic minimal surfaces as architectural and constructivecomponents.

A new TensiNet Working Group on Pneumatic Structures islaunched: Matthew Birchall (matthew.birchall@ burohappold.com) will be the leader of this Working Group.

The TensiNet association is part of the expanding topic oftechnical membranes and foils and hopes to further contributeto this evolution.


ESMERY CARON

KIEFER TEXTILE ARCHITEKTUR

ContextThe City of Colmar wanted tocover the open-air theater of itsExhibition Park in a lasting andesthetic way. The challenge wasto cover the existing Eastern andWestern tiers by installing atextile cover fixed on a metalframework with particularly shortdelays and taking into account theexisting equipment

and the constraints inherent tothe site. For example, the theateris located very close to the Colmarairport and part of theconstruction stands inside thearea concerned by the planes’taking-off and landing operations.The solution chosen by ESMERYCARON was to install very bigtextile cones suspended at 20mabove the theater stands.

Structure and installationThe plan dimensions of the two covering modules are about 55m by 2 X 65m, i.e. 2 textile covers of900m² and 2.2 tons each. The metalstructure supporting the tension fa-bric cover is mainly made of two tri-ple masts of 3.5 tons each, holdinga 135m long cable placed at an alti-

tude of about 20m. The textile co-vers are completely independentfrom the existing open-air theatrestructures by being tensioned onmain cables (56mm in diameter).The metal frames were treated bybath galvanization and bolted on-site. Erection of the elements wasperformed using a telescopic crane

Open-airtheater

Colmar, France

ContextBuilt in early 19th century the“Festung Ehrenbreitstein” is alandmark in Koblenz, locatedopposite of the famous “DeutschenEck” between Rhein and Mosel. Inone of the moats of the historical“Festung Ehrenbreitstein” a mainstage and stands for theBundesgartenschau 2011 (BUGA2011) have been located (Fig. 1). All kind of concerts will take placefrom April until October 2011. Themoat called “Retiriergraben” isabout 24m to 27m wide and 100mlong. The slope of the “Graben”ends in east direction at the“Landbastion”, is bordered to theNorth by “Kurtine” (both 25m highancient walls) and to the South by aramp in front of “ContregardeRechts”, which is opposite inclinedto the “Retiriergraben”, from 4 to12m height (Fig. 2). The moat opensup upwards. Client and investor was BUGA 2011,the owner is "BundeslandRheinland-Pfalz“.

ProjectKiefer. Textile Architektur provided arange of architectural solutions,until the client´s and owner´srequirements, which changed

during the design process, had beenachieved. The final brief was tocreate a temporary covering for astage of 8 to12m andapproximately 800 spectators in a

way that no attention is taken awayfrom the ancient masonry of thesurrounding buildings and the newconstruction is not attached to theold (Fig. 3).

Temporary roof structure Festung Ehrenbreitstein, Germany

Figure 1. Aerial view on the main stage © PP Koblenz

1

1

1800M² SUSPENDED STRUCTURE


installed close to the building site.The fabric was made in the work-shop and folded in a specific orderallowing a very precise on-site ins-tallation taking into account theneed for working at heights and thedimensions of the construction. Thefittings and various cables are madeof galvanized steel with a metalcore. Endings are of the rigid fork orthreaded end types.

! Olivier Dufour: olivier.dufour@esmery-

caron.com: www.esmery-caron.com

Project Name: Covering of the open-air theater, Exhibition ParkLocation address: Colmar, FranceFunction of the building: Outdoor facilitiesClient: Colmar CityYear of construction: July 2009 Project Manager: Colmar City Architecture DepartmentMetal framework: ACMLSupplier of the membrane material: FERRARI 1502 T2 1500g/m² - EN ISO 2286-2 standard

Membrane and framework Consultant: ARCORASupplier of the membrane: ESMERY CARONInstallation of the membrane: ESMERY CARON and EVEREST (3 weeks for a fitting team of 7)

Covered surface: 1800m²

The obvious solution was to build aroof • remarkable higher than the ramp,

to invite looking from the rampinto the stage;

• horizontally, in order to accentu-ate the falling and ascending linesalong the ramp wall;

• with respectful space betweenmasonry and roof edge;

• light and stringent seemingly,symmetrical main structure;

• translucent and smooth shapedelements.

Six portal frames in a grid of 7m,designed by three girder trusses,achieve minimum truss diameters.The horizontal upper girdercantilevers at both ends, in order tobase aside of existing foundations.Excavations for the new precastconcrete units had to be limited tomax. 50cm. The vertical trusses varyfrom 11 to 15m height. Their lowestpart is the adjusting element. Thestiffing of the structure inlongitudinal direction is induced byvertical cross bracing of each bay, incross direction by portal frames. Thefabric covers six bays of 7x 22m.Each bay gets an accentuated shapethrough two valley belts, whichdivide the bay into three elongatedareas. The middle one shows aclassical slightly barrel-shaped form.It effects a reduction of the visual

presence of the upper girder. Toreduce any imperfections in thefabric there is no assembling alongthe top girder but two welded kederstrips to hinder horizontalmovement. At both end frames thefabric is clamped by standardizedkeder-clamping profile from Tennectto allow for unpunched linearfixation. Membrane edges areframed with belts to underline thetemporary character.The valley belts are slightly curvedto increase the dynamic appearanceof the single bays. The belts are fixedto a rotatable supported bailconsisting out of steel tubes. Thesebails are used to tension themembrane. Due to the various angleat the fixation points of tie downtension struts a standardized ready-made product from Tennect wasused. The roofing structure wasfinally completed one day beforeopening ceremony at 15th of April.The complete design, engineeringand cutting pattern was carried outfrom Michael Kiefer, Tobias Lüdekeand Manfred Schieber at Kiefer.Textile Architektur.

! Michael KieferKiefer. Textile Architektur.Architekten und Ingenieure

: [email protected]: www.k-ta.de

Name of the project: Temporary roof structure Location address: Festung Ehrenbreitstein, GermanyClient (investor): BUGA 2011 and Rheinland-PfalzFunction of building: Temporary roof of main stage and standType of application of the membrane: Valleycable Saddleshaped Year of construction: 2011Architects: Michael Kiefer, Sebastian Fey Kiefer.Textile Architektur.Structural engineers: Tobias Lüdeke, Manfred Schieber Kiefer.Textile Architektur. Consulting engineer for the membrane: Tobias Lüdeke Kiefer.Textile Architektur.Main contractor & contractor for the membrane: Ceno-TecSupplier of the membrane material: VerseidagManufacture and installation: Ceno-TecMaterial: Verseidag B1951, PVC/ PES Typ 1Covered surface (roofed area): ca. 800m²Membrane assembling system: Tennect (Carl Stahl)

Figure 2. View from the ramp to the main stageFigure 3. View main stage © Kiefer.Textile Architektur.

2 3

3 3

2 2 3 3 3

Figure 1. Overview

Figure 2. External and internal view of thetwo covering modules

Figure 3. Installation


RESEARCH


Preliminary definitionsThe mechanical behaviour of materials isdescribed by relationships between stressesand strains. There exist however differentdefinitions, the most commonly used beingthe engineering stress s and the engineeringstrain e. They are actually simplifiedformulations and are only valid underinfinitesimal strains as they always refer to thematerial initial configuration. If the strainsexceed a few percents then the true stress σand true strain ε must be used. They representthe true material behaviour which is used infinite element analyses. The true stressaccounts for change in cross-sectional area byusing the instantaneous sample area. The truestrain accounts for an incremental sampledeformation where the new strain depends onthe updated shape. The comparison betweenboth definitions is illustrated in the part (B1) ofthe summary picture for the uniaxial tensionof an ETFE foil. The engineering stress andstrain are accurate enough in the initial linearpart. Above 2% of strain the difference withthe true stress and strain becomes significant.

Test procedures

• Uniaxial tensionSpecimen shape: standard dumbbellControl: traverse displacement(A1) The tensile load is measured with a loadcell while an optical extensometer measuresthe distance between two targets, allowingthe calculation of the engineering stress andstrain. The obtained stress-strain curve showsthe non-linear behaviour of ETFE foils. After aninitial linear part, it exhibit two points where

the stiffness significantly decreases denoted astwo yield points. The material undergoes verylarge deformations up to more than 400% atfailure. One can also mention that thebehaviour in the machine and transversedirection is very similar.(B1) The tensile true stress and strain can becalculated from the engineering stress andstrain. The Poisson's ratio ν is required. It ishowever not obtained from the uniaxial test,unless a strain measurement is operated in thedirection orthogonal to the loading. One caneither assume an incompressible materialbehaviour (ν=0.5) or use a typical value forETFE (ν=0.43 [7]). With this definition of stressand strain the increase of stiffness in thesecond half of the curve is even morepronounced. It is due to the reorganization inthe polymer structure, where the molecularchains are reoriented in the loading direction.As a result the material is no longer isotropic.

• Biaxial extension of cruciform specimensSpecimen shape: cruciformControl: load on each grip(A2) The load is measured for each grip with aload cell and two needle extensometersmeasure the strain in the central area of thesample. It can be seen from the results thatthe failure occurs at small strains, which is dueto the particular geometry of the sample. Thisearly failure of the specimen at about 7% ofstrain is the main disadvantage of this methodas it is not representative of the strains thatthe foil undergoes under large biaxial stresses.Biaxial machines however allow theapplication of different load ratios on thesample contrary to the bursting test.(B2) The biaxial true stress and true strain can

be calculated from the engineering stress andstrain. In that case the Poisson's ratio can beobtained from the biaxial tests if at least twoload ratios are explored.

• Bursting testSpecimen shape: circularControl: air pressure during the inflation(A3) The material behaviour is observed at thepole where a 1:1 load ratio is obtained. Thebiaxial true strains at the pole are directlymeasured by a 3D optical system using digitalimage correlation. The air pressure is measuredby a pressure sensor. Without post-processingno data is obtained as there is no mean ofmeasuring the stress in the material.(B3) The true stresses at the pole arecalculated based on pressure vessel theory.The bubble radius is estimated from thebubble shape measured with the 3D opticalsystem using a surface fitting. The foilthickness at the pole is estimated using theinitial thickness and the measured in-planestrains assuming that the material isincompressible (constant material volume).With the bursting test much higher biaxialstrains are reached. In that case failure occursat about 75% of engineering strain (true strainof 0.56). Therefore the bursting test must beused in order to observe the behaviour of thematerial and its failure under large biaxialstresses.

ComparisonIt is not possible to directly compare thestress-strain curves that have been previouslypresented. Each of these curves represents therelationship between only one stress compo-nent and one strain component. In reality, thematerial behaviour is defined by a relationshipbetween the stress tensor and the strain ten-sor. If one assumes a plane stress state wi-thout shear then for an isotropic material it isdescribed by 3 equations:

εx = 1 σx − ν σyE E

εy = − ν σx + 1 σyE E

εz = − ν (σx + σy )E

Under biaxial loading the strain in one directionis not only related to the stress applied in thatdirection but also to the stress applied in the

Mechanical properties of ETFE foilsComparison between uniaxial and biaxial test methods

ETFE foils have increasingly been used since the 1980's for roofs and claddings [1-4]. Their excellentlight transmission capability combined with their lightness and flexibility has broadened the scope oflarge transparent structures. The low weight properties of ETFE foils allow the design of structureswhich would have been impossible to build with conventional materials such as glass. ETFE is a polymer and therefore it exhibits non-linear stress-strain behaviour as well as rate- andtemperature-dependency [5]. Usually its behaviour is derived from uniaxial tensile tests [3-5]. In that case the behaviour is often measured in both machine (extrusion direction) and transversedirection. There is also an increasing interest for biaxial tests because they allow the observation ofthe material response under biaxial stresses as occurring in a tensile structure. In particular burstingtests have become popular during the last years [6] as they enable very large biaxial deformations.However, the benefits of biaxial testing over uniaxial testing have not been clearly demonstrated sofar for ETFE foils. Three tests methods are here compared [7]: uniaxial tension, biaxial extension ofcruciform specimen and bursting test. The study is focused on the deter mination of the materialmechanical properties from the experimental data. After an adequate post-processing these dataare compared and the advantages of each test method are discussed.

RESEARCH

S(P)EEDKITSRapid deployable kits asseeds for self-recoveryThe project ‘S(P)EEDKITS’ , which will start in 2012, will research rapid

deployable kits as seeds for self-recovery in disaster affected sites. A multidisciplinaryteam, consisting of different organizations throughout Europe, will develop a newemergency system of modular rapid deployable shelters, facilities and medical care.The kits must be transportable, modular and adaptable, must have a low cost andmust be high-tech in their conception but low-tech in use (Fig. 1 gives an example of afeasible kit. However the implementation of the kit, in the context of disaster reliefshelters, still needs to be investigated). Current kits will be scanned with regard tolarge transportation volumes and/or heavy weight. Out of this knowledge, newconcepts will be developed to drastically reduce the transportation volume and weight.The goal of these kits will be to provide temporary infrastructure, to establish thenecessary temporary services and to limit the damage to economic and social fabrics.The kits should provide infrastructure for different purposes, e.g. a hospital, a communication centre, water facilities or sanitation units. Also four different basicshelter kits will be designed and analyzed:

- A lightweight safe house unit: this shelter gives coverage for the very firsthours and need to be deployed by the communities

- A collective unit: a shelter which is usable for diverse purposes- A family house unit: this shelter will be used in the transitional period and

later, it can be referred to as the first version of a real house- A robust warehouse unit: a somewhat larger shelter for the humani-ta rian

organizations, it can be used for storage, offices, medical centers, etc.

The need for these kits becomes evident when thinking about the many disasters,both nature- and man-made, that occur worldwide. As a result, countless people arerendered homeless without any medical care, sufficient and clean water, decentsanitation or energy supply. In case of such an emergency situation, humanitarianorganizations (like the Red Cross, Red Crescent Movement and Médecins SansFrontières) emergency response units to rebuild these affected sites. These units aresent out immediately after a disaster strikes. Each unit has his own field of expertiseand consists of trained people and the necessary equipment (the ‘kit’) needed on site.The S(P)EEDKITS project wants to develop novel ‘kits’ that can be pre-positioned andmobilized more quickly and easily than existing ones.

The S(P)EEDKITS project will be a collaboration between : Centexbel (BE), Shelter Research Unit (LU), Netherlands Red Cross (NL), Sioen Industries (BE), Vrije Universiteit Brussel (BE), Technische Universiteit Eindhoven (NL), Politecnico di Milano (IT), De Mobiele Fabriek (NL), Waste (NL), Practica (NL),D’Appolonia (IT), Internationales Biogas und Bioenergie Kompetenzzentrum (DE),Millson BV (NL), MSF Nederland (NL) and Norwegian Refugee Council (NO).

! Jan Roekens - Vrije Universiteit Brussel: [email protected]

! Guy Buyle - Centexbel: [email protected]


REFERENCES[1] K. Moritz. Bauweisen der ETFE-Foliensysteme.

Stahlbau 2007;76(5):336-342.[2] S. Robinson-Gayle, M. Kolokotroni, A. Cripps, S.

Tanno. ETFE foil cushions in roofs and atria.Construction and Building Materials 2001;15:323-327.

[3] Y. Xiang, J. Li. Calculation and design of ETFEmembrane structures. In: Proceedings of the IASSSymposium, Beijing, 2006.

[4] M. Wu, J. Lu. Experimental studies on ETFE cushionmodel. In: Proceedings of the IASS Symposium,Mexico, 2008.

[5] K. Moritz. Time-Temperature-Shift (TTS) of ETFE-foils.In: Kröplin B, Oñate E, editors. InternationalConference on Textile Composites and InflatableStructures, Structural Membranes 2009. CIMNE:Barcelona, 2009.

[6] L. Schiemann, S. Hinz, M. Stephani. Tests of ETFE-foilsunder biaxial stresses. In: Kröplin B, Oñate E, editors.International Conference on Textile Com posites andInflatable Structures, Structural Membranes 2009.CIMNE: Barcelona, 2009.

[7] C. Galliot, R.H. Luchsinger. Uniaxial and biaxialmechanical properties of ETFE foils. Polymer Testing2011;30(4):356-365.

orthogo nal direction due to the Poisson's effect.As far as multidirectional stresses are concerned,the Von Mises formulas can be used to combinethe stresses and strains into an equivalent stressand an equivalent strain. The correspondingcurves are presented in the summary figure (C)for two uniaxial tests, two biaxial tests and onebursting test performed at room temperature atalmost identical strain-rates. Results are verysimilar up to the second yield stress. Above thesecond yield stress the large deformationsoccurring in the material change itsmicrostructure and therefore its mechanicalproperties. The material becomes anisotropic andits behaviour depends on the applied loading.

ConclusionIt has been shown that if an adequate post-pro-cessing is used then similar stress-strain curvesare obtained up to the second yield stress withuniaxial and biaxial test procedures. Thereforeuniaxial test can be used for measuring the mate-rial initial behaviour as they are very easy to per-form and do not require much material and time.If the plastic behaviour or the failure of the mate-rial must be investigated then biaxial stressesmust be applied. In that case the bursting test isthe most suitable method as it allows very largebiaxial deformations. This method is however li-mited to a single load ratio (1:1 for a circular sam-ple). In order to apply different load ratios abiaxial test machine can be used.

! Cédric Galliot: [email protected] ! Rolf Luchsinger: [email protected]

Center for Synergetic Structures : www.empa.ch/css

RESEARCH

Figure 1: Firststeps in thedesign of apossible disasterrelief shelter kit

IntroductionOver the last decades Hightex hasbeen dedicated to the constructionof innovative fabric roofs forsporting venues. One of the stadiumprojects for the EURO 2012 in theUkraine and Poland is the OlympicStadium in Kiev, which is currentlyundergoing a comprehensiverevitalization. The design for thereconstruction of the stadiumrespects the historical building withits significant filigree prestressconcrete upper tier tribunes from1968, by arranging thesuperstructure of the new roofsystem detached and with adistance to the existing seatingbowl. The most prominent part ofthe “Kiev Central Stadium” will beenclosed with a new delicate glazingfaçade and, like an exhibit in a glasscabinet, will be put in perspectivewith lighting. This is how thearchitect von Gerkan, Mark andPartner (gmp) describe their design.With its fabric roofing systemshaped by filigree flying struts intoan ocean of conicals covered withlight domes the Olympic Stadiumshould receive a unique anddistinctive identity as an urbanlandmark within the texture of thecity centre of Kiev. The mainstructural system of the roof derivesfrom the spoke wheel principal. Itconsists of two outer compressionrings, steel plate box girders, whichrest on the 80 kinked columns, alsomade of tapered steel box girders.80 cable trusses of upper and lowerradial cables, coupled with hangercables build up a light cable net,which are anchored into thesecompression rings and meet at thecentre in a tension ring. The tensionring encases approximately theplaying pitch. The horizontal forcesare balanced out between the outercompression rings and the innertension ring. The vertical forces are

transferred from the cable net intothe 80 columns and into thefoundations. 80 axes are veryuncommon for stadium roofconstructions. Similar projectsusually make do with about half thenumber of axes. One of the reasons for this designwas the original material choice ofthe main membrane. First conceptsenvisioned the use of a single layerof ETFE foil. It has much lowerstructural capacity than typicalcoated fabrics, which are usuallyused for stadium roofs. While thefabrication and installation of thesteel columns was already underway, the material choice of thehighly transparent foil wasdismissed over the course of theplanning. The 80 columns stilldominate the overall impression ofthe architecture of the stadium andwill impress a unique characteronto the stadium. The roof cover,the translucent membrane fieldelements, will now be made ofPTFE coated Glass fabric. Eightflying struts in each bay impress aseries of conical shapes into themain membrane. These flying strutsflare up like a funnel and the mainmembrane is connected to the toprings of the flying struts. The round

openings between 2.5m to 3.2mdiameter are covered with lightdomes spanned with ETFE foil. Thisgenerates a unique translucentroofing landscape with in total 640light spots. For this project Hightexis responsible for the cablestructure and membrane roof.

Cable structure (Fig. 1 to Fig. 5)The ten ring cables are 115mmdiameter also fully locked galvancables and have a total length ofabout 469m each. They are bundleinto two layers of 5 cables each and

connected to the so called ringcable connectors. These are 2.5tcastings, which have two verticallyarranged cleats, connect the upperand lower radial cables to the ringcables. The upper and lower radialcable, also fully locked galvancables are interconnected with 8 hanger cables each build up the80 cable trusses. The cables arefabricated with fork terminals ateach end. One end connects to thering cable connector and the otherend connects to cleats at the upperand lower compression rings.


HIGHTEX GMBH

RECONSTRUCTION

Olympic Stadium Kiev, Ukraine

Installation of the cable structure Figure 1. Connection of upper radial cable andring cableFigure 2. Layout of ring cable

Figure 3. Lifting of spreader barFigure 4. Cable net roof constructionFigure 5. Pinning of fork terminal

1 3 5

4 2


For the installation the radialcables and ring cables are laid outin the stadium bowl. The open endsof the radial cables are fitted withtemporary spreader bars to take onthe lifting equipment. The upperradial cables are pulled towards theupper compression ring with strandjacks and pinned. This process willlift the cable net completely offthe ground. Then the last 1.5m ofthe lower radial cables are pulledwith the threaded bars and hollowhydraulic cylinders towards thelower compression ring until allcables can be pinned. This processis called the “big lift” and takesabout 30 days.

Membrane structure (Fig. 6 to Fig. 11)For the next installation step themembrane roof panels are fittedonto the completely stressed cablenet. Each of the 80 bays consists ofabout 600m² PTFE/Glass mem -brane panels with an approximateweight of one tone. The membrane

fields will be cut from the virgin rollmaterial, welded and assembledready-to-install off site in thefactory. They get packed, shipped tosite and directly lifted onto the roof.The membranes are unfurled fromthe rolling rack on the lowercompression ring. The membrane isthen connected at the circular cutouts to the already positioned butlowered flying struts. The finalshape and prestress is brought intothe membrane by lifting the flyingstruts into their final position. This process is assisted by hydraulicjacks at the footing of the flyingstruts. The roof structure iscompleted after all the 640 lightdomes are mounted.

! Gregor Grunwald: gregor.grunwald@

hightexworld.com! Markus Seethaler

[email protected]

: www.hightexworld.com© Pictures: Hightex GmbH

Installation of the membrane

Figure 6. Beginning of membrane installationFigure 7. Roof view from belowFigure 8. High point installation

Figure 9. Roof top viewFigure 10. Different stages of high pointinstallationFigure 11. Installation of the high pointclamping profile

Name of the project: Olympic Stadium Kiev Location address: City of Kiev, UkraineClient (investor): Olympic National Sports Complex, UkraineFunction of building: sport stadiumYear of construction: 2010-11Architects: gmp • Architekten von Gerkan, Marg und Partner,

Personal Creative Architectural Bureau Y. SerjoginStructural engineers: SBP – Schlaich Bergermann und PartnerManufacture and installation of cable net and membrane: Hightex GmbHSupplier of the membrane material: Verseidag-Indutex GmbHMaterial: PTFE-GlassCovered surface (roofed area): approx. 45.000m²

6 7

9

11 10

8

Anticlastic minimal surfaces as elements

in architectureIntroductionOn the basis of the research of Frei Otto and his team at IL (University of Stuttgart)and the resulting exceptional pioneerconstructions, building with textiles as analternative to traditional materials like wood,stone, steel, glass, and concrete wasrediscovered during the last decades. Deriving from self organizing forms of MinimalSurfaces, prestressed, spatially curvedMembrane Structures were up to todaymainly used for wide span, lightweight-structures. For this reason membranestructures tend to be seen from a structural or material point of view only. In contrast to our right-angled, conventionallybuilt environment the desire for fluent “soft” spaces in architecture cannot beoverseen any more. The possibility to createlight and fluent spaces as a symbiosis of form and structure offers new qualities and chances in the architectural design of residential or office buildings for example.

SubjectThis article presents the overview of theresearch on spatially curved Minimal Surfacesthat considers the infinite possibilities ofmembrane forms as elements in architecturein combination with common building-technologies and shows new capabilities indesigning and creating spaces. Seen as anelement in the design of architecture theseanticlastic, fluent forms caused by structuralconditions, follow the rules of formfinding inits initially (by Frei Otto) defined sense. Very often we misuse the term „formfinding“.What Architects mostly mean and do is a mancontrolled process of shaping - a process thathappens on a consciously controllable andformal level. In contrast to the man-controlled process of shaping, forms that arearising from self organizing processes can onlybe influenced by the design of theirboundaries. The form itself can only be foundand represents the result which cannot bemanipulated. The architect finds himself in theunusual position of a creative “formfinder”instead of the “shaper”. The fluent forms of Minimal-Surfaces arefascinating by their variety, structuralperformance, reduction to the minimal interms of material use and resources and theirspecial fashion-resistant aesthetics.


SOFT.SPACES Together these parameters represent thecommon basis of a potential design or designconcept and characterize its grade ofsustainability.

ObjectivesSince self organizing processes follow preciserules and contain optimization by theirnature descriptions and especially inarchitecture illustrations of these rules can beused as design tools [1]. To find out about thechances for an architecture between „hard“and „soft“ morphology, basic research on thesystematic determination of very differentboundaries - the interface betweenmembranes and common constructiontechnologies - enables the opportunity toanalyze anticlastic Minimal Surfacesregarding form and curvature. Vice versa weget an idea of the correlation between 3d-curvature, deflection and determinedboundary and further on an idea of formaland structural behavior. In this context theassessment and visualization of the Gaussiancurvature, which were adapted especially tothis research, played an important role.

Special Specifications1 Minimal surfaceAll experiments are restricted to forms thatcan be derived from the results of soapfilmmodels – the Minimal Surface. As long asboundary conditions are not changed,Minimal Surfaces can be arranged as a unityarbitrarily in space without changing itsform/geometry.

2 InterfaceLinear, maximal 2dimmensionally curved,bending resistant, line supported boundaries

turned out to be the ideal interface betweenmembranes and common constructiontechnologies. All further experiments wererestricted to boundaries of that kind.

3 Membranes as an integrativeelementMembranes are seen as an integrativecomponent of architecture and are directlyconnected to other elements of commonconstruction methods. In terms of structuraleffectiveness the surfaces themselves areconsidered to be highly efficient by theirspatial curvature but not to be load bearingelements for other structural membersalthough newest approaches in the author`sresearch are dealing with this possibility.

InvestigationsThe range of exploration covers wall-likeelements, T-shaped connections, solutionsfor vertical, horizontal and free corners andthe tubular entities of the Catenoid.

MethodsBesides physical (Fig. 1) and soapfilm models(Fig. 2) mainly digital experiments (Fig. 3)were used for the interpretation and theverification of results. Soapfilm models weremainly considered to fulfill a controlfunction. Digital models were essential forthe analysis and evaluation of forms (sectioncurves, their diagrammatic overview, analysisof angles in space,…) of Minimal Surfaces. Inthis context the assessment and visualizationof the Gaussian curvature (Fig. 4), which wereadapted especially to this research, made itpossible to compare and to draw one`sconclusions on different forms and theirstructural behavior.

Results of investigationThe results of physical, soapfilm and mainlydigital experiments show surprising andpartly new correlations between form andboundary proportions and so far unknownrules of the self organizing processes ofMinimal Surfaces – especially in the field ofthe Catenoid. The overview and thecomparison of the results as well as thepossibility of a targeted selection cantherefore be the basis for creativeapplications.

1 Minimal surfaces betweenstraight lines and boundariesconsisting of segments of a circleAll experiments related to this series (Fig. 5)show, that for this boundary condition it isnot possible to find a fully anticlastic curvedMinimal Surface. Those surfaces which showfew flat areas are generated within arelatively small spectrum of boundaryconditions. They concentrate on boundaryconditions consisting of semicircles with adiameter that corresponds to the distance ofthe boundaries. Independent of theamplitude of the curved boundary MinimalSurfaces tend to be flat in the near of thestraight line boundary. Experiments show that in average up to 96%of the horizontal deflection that was given bythe curved boundary is disappearing halfwaybetween the upper and lower boundary.Horizontally shifted boundaries (Fig. 6) canbe interesting from the architectural point ofview. But in terms of anticlastic GaussianCurvature this always means a furtherincrease of flat areas.

Figure 1. Physical study model -showing catenoids betweenshifted circular rings

Figure 2. Sequence of SoapfilmModels

Figure 3. Digital model of acatenoid between circular ringsand Visualization of GaussianCurvature

Figure 4. Special unification ofassessment and visualization ofthe Gaussian curvature for thisresearch

Figure 5. Minimal Surfacesbetween straight lines andboundaries consisting ofsegments of a circle

Figure 6. Horizontally shiftedboundaries

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RESEARCH

2 Minimal surfaces between boundaries consisting of segments of a circleIn this case the boundaries of wall like MinimalSurfaces can have the same direction or theycan be arranged inversely. Horizontally shiftedboundaries represent special cases and showinteresting architectural effects. The horizontaloffset can be in longitudinal, cross or diagonaldirection.

Minimal Surfaces between boundariesconsisting of segments of a circle in the same directionBoundaries that are curved in the samedirection (Fig. 7) generally effect stronganticlastic curvature of Minimal Surfaces.Boundary conditions consisting of semicircleswith a diameter that equals the distance of theboundaries can be qualified as 100% spatiallycurved. Section lines show the smallest circleof curvature exactly on half height andharmonic development of the surfaces (Fig. 8).

Minimal Surfaces between boundariesconsisting of inversely arranged segmentsof a circle Curved and inversely arranged boundaryconditions effect anticlastic curvature coveringmost of the surface, even if the boundaries havelittle oscillation from the longitudinal axis. Themostly curved surface can be developed withboundaries consis ting of semicircles with adiameter of 2/3 of the distance of theboundaries (Fig. 9). Areas with little spatialcurvature can first of all be found exactly at themaxima of boundary curvature and on halfheight. Starting from the ideal case these flatareas increase with increasing as well as withdecreasing diameters of the base-circles.Surfaces arising from boundary conditions withbase-circles bigger than the height show

flattened vertical stripes (Fig. 10) whereasflattened horizontal stripes (Fig. 11) appear withboundaries consisting of segments of circleswith less than the height.

3 Membranes cornersRegarding corner solutions, boundaries can bearranged horizontally (Fig. 12) or vertically (Fig.13). The free corner (Fig. 14) describes a specialcase. The vertical and free membrane cornerwill not be described in this article..Horizontal membrane CornerAll executed experiments with horizontal right-angled corners show almost constant surfacecurvature (Fig. 15) and deflection in the area of

the corner (Fig. 16). This happensindependently form the leg length and frombeing arranged symmetrically or asym metri -cally. The section lines of digital models arecongruent (Fig. 17). Leg length being shorterthan the height cause surfaces with littleanticlastic curvature. Surfaces of maximumspatial curvature in all areas can be achievedwith a ratio 1/1 to 3/2 of leg length/height.Increased leg length causes areas with littleanticlastic curvature at the end of the legs.

4 T-connectionSurfaces meeting in a T-connected boundary(Fig. 18) generate a Y-intersection (Fig. 19).


RESEARCH

Figure 7. Boundary configurations consisting ofsegments of circles having the “same direction”Figure 8. Vertical section of digital models andtheir circles of curvature, all having their centerat half height.Figure 9. EM KK 2/3 _ 1,00HK ggsFigure 10. EM KK 2/1 _ 0,50HK ggsFigure 11. EM KK 1/2 _ 1,00HK ggsFigure 12. Horizontal CornerFigure 13. Vertical CornerFigure 14. Free Corner 7 8

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Figure 15.Horizontal corner withratio of 1 1 1(leg/leg/height)Figure 16.Horizontal corner withratio of 111 GaussianCurvatureFigure 17.Horizontal section lines„Horizontal MembraneCorner“ – in comparisonFigure 18.Geometry of right angledT-connectionFigure 19.Minimal Surface generatedfrom a right angled T-connection

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RESEARCH

This happens independently from the angleof the boundary connection. The 3 differentparts of the Minimal Surface meet with 120°and form an arch-like intersection. This archis less curved at its angular point and morecurved the closer it is to the T-connection ofthe boundary. „In very special cases only, acircular intersection can be formed .” [2]

These special cases were used to formpressure resistant arches for real structures.

Right-angled T-connectionIn terms of right-angled configurations theleg length of H (0) has no influence on theform of the generated Minimal Surface aslong as it is longer than the deflection of theY-intersection. This happens to be the same,independently from the wings beingarranged symmetrically or asymmetrically.

> Symmetric wing lenght [FL]: For symmetricwing length [FL] one can determine that themagnitude of the Y-intersection is directlyconnected to the ratio of wing length andelement length. For all boundary conditionswith FL ≥ EL/2 the magnitude of the Y-intersection equals 20,6% of the elementlength. For wing length shorter than theelement length, a nonlinear behavior of theY-intersection can be determined. So theboundary condition FL=EL/2 represents theborderline between linear and nonlineardevelopment of displacement in thedirection of H (Fig. 20). A square geometry inplan causes evenly distributed curvature inthe surface (Fig. 21). The curved Y-intersection is similar to abasket arch (Fig. 22). Starting from a squaregeometry in plan increased wing lengthresults in the generation of insufficientlycurved areas at the ends of the wings. On theother hand there are no effects on the form,radii of curvature of the Minimal Surface andthe transitional zone with anticlasticcurvature to insufficiently curved areas doesnot move. The enlargement of the elementlength which corresponds propor tionally to areduction of the wing length causesinsufficiently curved areas which are merged

together in the element middle. Stronganticlastic curvature is limited to the areas ofthe T-connection of the boundary.

> Asymmetric wing lenght [FL]: Spatiallycurved Y-intersections and spatiallycurvature of all partial areas are generated byasymmetric wing length. The horizontalcomponent of the deflection always occursin direction of the larger wing.

Non-right-angled T-connectionsWhen using T-connected boundaries withangles different from 90° the surface of H(Fig. 23), which is totally flat for the 90° case,will be spatially curved too. Increasingdeviation of 90° goes along with increasinganticlastic curvature of surface H (Fig. 24).The formally interesting Minimal Surfaceswhich develop as a result of a T-connectionwith a not at right angles deviating surface Hshow spatially curved intersection lines. Themore the angle differs from 90° the more theanticlastic curvature of H increases. At thesame time the vertical deflection of theformer horizontal parts decreases.

5 CatenoidThe shape of the catenoid is basicallygenerated by a catenary that rotates arounda longitudinal axis. It is the only rotationalbody that can be minimal surface at thesame time. As we know from SFB230 themaximum attainable height of a catenoidspanning two circular rings is approximately1,3 times the radius of a ring. [3]

For conceptual designs in architecture,boundaries different from two identicalcircles but with different diameters, notbeing arranged in one axis and/or not beingsymmetrically arranged are needed. So themaximum attainable heights of catenoidswith different boundary geometries andarrangements were examined. New rulescould be found for major boundaryconfigurations [4]. The resulting diagrams canbe scaled at will.

Catanoids between circular rings of different diametersStarting from the extreme of 1,3 times theradius of a ring the maximum height of a

Figure 20. Displacement of vertical section lines from rightangled T-connection with symmetric wing length and

different element length [EL]

Figure 21. T-connection with square boundary geometry FL = EL/2

Figure 22. Linear increase of displacement at increasingelement length up to EL/2=FL, then nonlinear

Figure 23. T-connections different from 90°

Figure 24. T-connection with an angle of 60°

Figure 25. Vertical section lines T30°, T45°, T60°, T75°

Figure 26. Spatially curved intersection line for T60°

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24 23

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catenoid is decreasing if one of the ringsdiameter is decreasing (Fig. 27). Fig. 27 also illustrates that upper ringssmaller than 1/5 (upper ring /lower ring)effect very little maximum attainableheight and surfaces with little GaussianCurvature at the same time. Severalexperiments showed that all the attainable maxima in dependence from the given diameters are located on acommon circle - the extreme value circle.This circle again is in direct proportion tothe circular base ring (Fig. 28). The developed diagram allows adetermination of the maximal attainableheight when the diameters of the two rings are given. The other way round the maximal diameter of the upper ring can be found by predefining the desiredheight and the diameter of the base ring (Fig. 29).

Case-Study A (Fig. 30)A catenoid is perforating several floorsand creates a courtyard situation. Its position is chosen the way that theground floor gets a spatial incision whilst theother floors are still connected by a catwalkbetween catenoid and facade.

Case-Study G (Fig. 31)The form of the catenoid is intersected witha rectangular building. In this case thecatenoid was tilted in the direction from(left) and towards (right) the building. Forthis reason the opening in the façade openson top and narrows to the sky inside thecourtyard (left) and vice versa (right).

Catenoids between shifted circularringsA displacement of the boundary ringseffects lower maximum heights ofcatenoids (Fig. 32).

This correlation also follows precise rules.The interrelation of displacement ofboundary rings and maximal attainableheight of the catenoid can be found oncircular movements defined by the centerof the base ring and the diameter of therings (Fig. 33).

At the same time we can observe that adisplacement of more than ¾ of thediameter of the rings effects areas withlittle Gaussian Curvature. Strongly curvedareas can always be found at half height ofthe catenoid. A displacement of 1 diameter

of the boundary rings cannot be attainedwith a catenoid but forms two separatedsurfaces within the rings.

Case-Study K (Fig. 34)A horizontal displacement of one of theboundaries of the catenoid enables a spatialmovement. For the fact that the base rings ofdisplaced catenoids have equal diameterthey can act like swivel plates. This wayvertical connections or orientation to naturallight can be solved.

Catenoids between square rings of the same side lenghtCompared to catenoids generated by twocircular rings, catenoids between two equalsquare rings (Fig. 35) are having theirmaximum height at 1,44times of the sidelength of the square (Fig. 36). In analogy tocatenoids between circular rings the maximalattainable height or the smallest possibleupper square can be found on a commonextreme value circle too.

Catenoids between a square anda circular ring Catenoids between a square and a circularring don`t follow an extreme value circle but

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31

34

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3332

2928


a catenarylike line starting from the center ofthe square and going through the quadrantof the upper circular boundary. The maximal attainable height equals1,39times the radius of the inscribed circle of the square respectively half of its side length. This is valid for configurationswhere the circle is the incircle at the most.

Congruent cut-outs from Minimal Surfaces of CatenoidsAll executed investigations have shownthat each randomly selected cut-out from a Minimal Surface of a catenoid will be a Minimal Surface with equalposition in space and equal curvature of the surface itself. This can be explained by the absolute identical stresses in alldirections of Minimal Surfaces. The example in Fig. 37 is showing arandomly selected closed curve that is projected on the surface of a catenoid.For this reason this curve is exactlymatching the surface of the initial catenoid. By defining this curve as a new boundary line the new surface within this boundary is also matching the surface of the initial catenoid.

Case-Study M2 (Fig. 38)The intersection of several catenoids ispossible without changing of form of thedifferent parts. This way 3dimensionallycurved ridges are developed by the inter sec -tion line.The definition of the new boundarycan be found as described before, but it canalso be found by intersecting differentindependent catenoids or by intersectionwith other forms. As shown in case-study M2(Fig. 38) catenoids even don`t need to havethe same position in space or the same size.This way a lot of possibilities are open for apotential design in architecture.

Conclusion on research, case-studies and experimental structuresThe characteristics that Minimal Surfacescan be proportional scaled and that apredefined cut-out of minimal surfacekeeps unchanged multiplies thepossibilities for the design. Using the foundrules case studies give an idea of theinfinite possibilities that are open to createvery special „soft spaces”, with newarchitectural qualities like shown in abovecase studies and experimental structures(Fig. 39 to Fig.41) and furthermore.

PerspectiveLatest approaches are dealing with alter na -tive boundary-conditions and with softwareimplementation in terms of scripting foundrules[5] (Fig. 42). The aspect of geometricalregularity a visual irregu larity of anticlasticMinimal Surfaces is subject of an actual re -sear ch project. An investigation on thecor re lation of self organizing forms, theirclose relation to nature and their aestheticvalues also seems to be interesting questionsfor the future.

! Günther H. FILZ: [email protected]© www.koge.at

RESEARCH

REFERENCES[1] Filz, Günther, “DAS WEICHE HAUS soft.spaces”,

Dissertation, Leopold-Franzens-Universität Innsbruck,Fakultät für Architektur, Juli 2010

[2] Otto, Frei, IL 18, Seifenblasen, Karl Krämer Verlag,Stuttgart 1988

[3] Mitteilungen des SFB230, Heft7, Sonderforschungsbereich230, “Natürliche Konstruktionen – Leichtbau in Architekturund Natur“, Universität Stuttgart, Universität Tübingen,Sprint Druck GmbH, Stuttgart 199

[4] Filz, Günther, “minimal is maximal _ soft.spaces”, accep tedfor Paper Proceedings, IABSE-IASS Symposium London 2011“Taller, Longer, Lighter”, London, 20-23 September 2011

[5] Filz, Günther ; Maleczek, Rupert; “From Basic Research toScripting in Architecture”, Workshop at “2nd InternationalConference on Architecture and Structure” and “3rdNational Conference on Spatial Structures“, Centre ofExcellence in Architectural Technology of the University ofTehran, Iran, 15-18 June 2011.

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40

Figure 27. Change of form and change of GaussianCurvature of a Catenoid with decreasingdiameter of upper ring and therefore decreasingheight

Figure 28. 3dimensional diagram for catenoidsbetween circular rings of different diameters

Figure 29. Soapfilm model and diagram forcatenoids between circular rings of differentdiameters

Figure 30. Case-Study A

Figure 31. Case-Study G

Figure 32. 3d view of overlayed catenoids betweenshifted circular rings showing the circularmovement of the upper ring and thedependence of horizontal displacement of therings and the loss of height.

Figure 33. Side view of overlayed catenoids betweenshif ted circular rings showing the circular move -ment of the upper ring and the dependence ofho ri zontal displacement of the rings and the lossof heigh

Figure 34. Case-study K

Figure 35. 3dimensional diagram for catenoidsbetween square rings of the same side length

Figure 36. Diagram for catenoids between squarerings of the same side length

Figure 37. Congruent cut-outs from MinimalSurfaces of Catenoids

Figure 38. Case Study M2

Figure 39. “Cube of Clouds” experimentalstructure in model and in scale 1/1 by koge, Institute of Structure and Design,

head E. Schaur, University of Innsbruck,exhibited and published at Premierentage 2005,Best of 2005 and Ziviltechnikertagung 2005

Figure 40. “Cut.enoid.tower” - experimentalstructure with a height of about 13m in scale 1/1.The distorted appearance is generated by theinteraction of pin-joint columns, which work oncompression only and different versions ofprestressed catenoids.

Figure 41. “minimal T”– structure shows thepossibility to deflect surfaces that were flatbefore being assembled by using specialgeometries in arrangement

Figure 42. Grasshopper script “Catenoids betweenhorizontally shifted circular rings”

41 42

TENSINEWS NR. 21 – SEPTEMBER 2011TENSINEWS NR. 21 – SEPTEMBER 201116

ContextLAVA’s Home of the Future is ashowcase for future living, withnature, technology and man in anew harmony. The Home of theFuture will start construction in late2011 on the rooftop of a newfurniture mall in Beijing, China (Fig.1).

ProjectAn ETFE geodesic skydome providesa year-round microclimate thatopens up the home to a garden filledwith sun, light and fresh air, awayfrom the pollution and noise of thecity (Fig. 2). Visitors will experiencefifteen different living spaces, frominternal/external bathroom zones tokitchens flowing to veggie patchesand barbeques to sunken bedroomswith dream inducing lighting. Atnight the home and the tropicalgarden turn into an otherworldlyexperience, with the underlyingtechnology, the electronic veins ofthe system, coming to life.Thedesign is inspired by nature’sefficiencies – corals, cells andbubbles - and creates an environ -ment where technologies areinvisibly integrated to satisfy every -day needs and senses. Its fluid design

and organisational strategy based oncells is easily modified to suit specificrequirements. The Home of theFuture integrates the latest improve -ments in comfort and instantaneousinformation technology with a spacethat embraces nature.

Chris Bosse, Director of LAVA says:'The Home of the Future acts as ametaphor for the questions of ourtimes, our relationship with nature,with technology and with ourselves'.LAVA’s Home of the Future is ashowcase for future living - itbalances man’s needs with natureand technology in perfect harmony.

Team LAVA: Chris Bosse, TobiasWallisser, Alexander RieckLandscape: AecomEngineering support: ArupETFE: Vector Foiltec

! Jane Silversmith : [email protected]: www.l-a-v-a.net

La Plata StadiumArgentina

A COMPLETED ROOF MADE OF 30.000M² HIGH-LIGHT TRANSMISSION MEMBRANESSAINT-GOBAIN BIRDAIR

Home of the FutureA SHOWCASE FOR FUTURE LIVINGBeijing, China

Figure 2. Section trough the ETFE geodesic skydome. ® Doug and Wolf

Figure 1. Visualization Future Living day and night. ® Doug and Wolf

ContextMore than 10 years ago, over 30.000m² of ULTRALUX® I ArchitecturalMembrane was manufactured to top a new stadium in La Plata, Argentina.For various reasons, the stadium was built but the roof was never installeduntil last year . The roof features a unique style, a double cable dome whichprovides a figure eight shape, was added to complete this beautiful stadium. Today, the stadium is completed and looks amazing (Fig. 1).

MembraneFor the membrane the high translucency architectural membrane ULTRALUXwas chosen. ULTRALUX is made of fiberglass and polytetrafluoroethylene(PTFE) and provides about 25% light transmission as opposed to standardproducts which provide 10 to 16% light transmission. ULTRALUX ismanufactured by Saint-Gobain in the Merrimack, NH plant.

Cable structureBirdair engineered, fabricated and oversaw the installation of the cablestructure and fabric roof. Birdair’s steel cable systems was used. Toaccommodate the unconventional geometry of the stadium, the main roofstructure was formed using tensioned steel cable hoops at three differentlevels, along with vertical columns, diagonal cables, and ridge cables. Thisprestressed tensegrity design features a figure-eight-shaped central openingthat resists global distortion using tension. Consequently, the roof deck isextremely stiff, similar to the way a drum skin is stiffened by tensioning.

! Roland Keil: [email protected]

Saint-Gobain performance Plastics: www.chemfab.com - www.sheerfill.com - www.birdair.com

Figure 1. Aerial view of the completed roof Figure 2. Installation of the cable structure © BirdairFigure 3. Inside view of the completed roof © Birdair

LABORATORY FOR VISIONARY ARCHITECTURE LAVA

Name of the project: La Plata StadiumFunction of building: sport and cultural eventsYear of construction: 2011Architects: Roberto FerreiraEngineer: Weidlinger and Associates, New York, New YorkGeneral contractor: Astillero Rio Santiago, Rio Santiago, Ensenada, ArgentinaSupplier of the membrane material: Saint-GobainMaterial: ULTRALUX® I Architectural MembraneCovered surface (roofed area): 30.000m²

TENSINEWS NR. 21 – SEPTEMBER 2011TENSINEWS NR. 21 – SEPTEMBER 2011 17

IntroductionThe Rhein-Galerie, located directlyon the bank of the river Rhine inLudwigshafen, provides anattractive place to shop and havefun. Around 130 specialist retailersprovide a modern variety ofproducts and services over30.000m² of sales space spread outover two floors. The adjacentRheinpromenade directly connectsthe Rhein-Galerie with the Rhine.

Imposing roof architectureParticularly memorable is themembrane roof designed to createan architectural link between theriver and the rhythmic oscillationsof the building’s lateral arches. Thetranslucent roof covers the entireshopping centre and lends thearchitecture a distinctive character.

High-quality materials for optimum interior conditionsThe decision was taken to use PTFE(Teflon®) coated glass fabric. Thismaterial’s long life is not its onlyimpressive trait. The Teflon®surface coating also makes it easyto clean, because ordinary dirt anddust is simply washed away by rain.The high level of sunlight reflectedoff the surface as a result of thewhite colour ensures that the areaunder the membrane roof is heatedless, but also ensures that a highlevel of light from outside canpenetrate the roof, as was desired.

Elegant structure with unique detailsThe supporting structure of thisextraordinary building is an elegant,three-dimensional, curvedstructure supported by a weldedsteel tube girder frameworkconsisting of column supports uponwhich arches and frames were built.There are a total of 68 discretesurfaces, which are cladded withmechanically pre-stressedmembrane sheets. The roof surfaceis left open above the interlockingelliptical courtyards of the interiorin order to ensure optimum lightingfrom outside. The membrane sheets were fixedinto place using steel fixture stripsfor each sheet, following the curvedform of the steel structure. Themembranes were joined usingaluminium sections that wereproduced specially for this project,and these were also pre-cast. The joints between the sectionswere sealed by mounting them onmodified extruded neoprene stripseals. The aluminium sections allow

each of the membrane sheets to besubjected to linear pre-stressingand fixed in place in a straight linewithout having screws penetratethe surface of the membranes.

Produced precisely to orderOne of the core tasks was toproduce the 68 membrane sheetswith sizes of between 70 and380m² in the Greven factory in away that enabled them to be fitteddirectly at the shopping centrewithout any further modifications.This advance production processused the 3D model provided by thesteelworker as the basis, togetherwith jointly agreed productiontolerances. In order to ensure thatthe membranes were sufficientlypre-stressed, thereby providingthem with sufficient long-termstability against snow and wind, thetensile properties of the coatedfabric were determined using biaxialtesting. This process enabled each ofthe sheets to be produced preciselyin advance while the construction ofthe steel structure was ongoing.

Planning the fitting process –down to the last detailThe panels were fitted by a team of experienced industrial climbers.Because the coated glass sheetswere so susceptible to kinking, a refined and precise plan for fittingthem had to be developed. Firstly, the sheets were spread out on a pre-mounted support net and protected from exposure to the wind. They then had thespecial aluminium sectionsattached to all sides. The linear pre-stressing of around4KN/m had to be applied in stepsto ensure that the material was not damaged. It was only at the end that the aluminium sectioncould be attached to the supporting steelwork with thesealant strips and correspondingscrew joints. The three-dimensional nature ofthe structure and the necessity ofdoubling over and reinforcing theedges meant that around33.000m² of material wereprocessed in order to cover around24.000m² of surface area. Thefitting took a total of eight months.

! Bosse Anne : [email protected]: www.ceno-tec.de© Illustrations/photos

ECE Projektmanagement GmbH & Co.KG

Membrane roof Rhein-Galerie in Ludwigshafen, Germany

CENO-TEC

Name of the project Membrane roof for the Rhein-Galerie in LudwigshafenLocation address Ludwigshafen, GermanyClient Rhein-Galerie GmbH & Co.KG, HamburgYear of construction 2010Architect ECE Projektmanagement GmbH & Co.KGGeneral contractor Ed. Züblin AGManufacturer membrane roof Ceno Tec GmbH Textile ConstructionsMaterial Glass PTFECovered area 24.400m² – 60 facade fields and 68 roof fields


ContextTo protect the approx. 5.000 yearsold temple complexes Hagar Qimand Mnajdra on the island of Maltaagainst erosion, two membranestructures have been developed,which now cover and protect thearcheological excavation. For thousands of years the stonycult sites have been overwhelmedbefore in 1839 their unearthing wasstarted. Hagar Qim and Mnajdra aresituated at the South coast of Maltaat only 500m distance. Builtbetween 3.600 and 2.500 B.C., the sites made of lime stone blocksbecame UNESCO-world heritagesites in 1992. Since their excavationthe rough environmental conditionshave affected the temples HagarQim and Mnajdra strongly. The softlime stone impended anaccelerated dilapidation by saltyrain and high variations intemperature. In the year 2000 a

group of scientists suggested tobuild a conservation andinterpretation protection accordingto UNESCO regulations over thecult sites. This is weather protectionon the one side and theencouragement of attentive visitor'sbehaviour on the other side toprotect the fragile temple sites fromfurther dilapidation.

International UNESCO competitionThe design of these roofs has beenpart of an international UNESCOcompetition which was won by theSwiss architect Walter Hunziker in2003. Supported by the engineeringoffice KTA the original steepmembrane roofs with one archbecame flat roofs with two inclinedarches. formTL was contracted withthe final design and the structuraldesign as well as the pattern designby the North-Italian general

contractor and membranemanufacturer Canobbio SpA.

ProjectThree important preconditions hadto be taken into account: the roofsneeded to be deconstructablewithout visible effects after therestoration of the sites in 25 or 30years and their design had to followthe astronomical alignment of thetemples. At certain times of theyear the roofs should not impedethe insolation at certain dates likethe summer and winter solstice.And they should offer themaximum weather protection. The geometry was only partly givendue to the individual topography,but could be solved similar indesign: The developed structuresconsist of two center positioned,slightly inclined steel arches.Between the arches and to the sideframes a cable net with membrane

FORM TL MEMBRANE ROOFS SHELTER

Stone-age templeMalta

panels is spanned. The biaxial cablenets allow to realize the archeswithout any additional stabilizationcables.

During the design process the roofshapes have been adapted to thesituation on site. Step by step thestructures have been adjusted withthe gradually generateddimensional geometrical survey ofthe temples and their surroundingsuntil the roofs fulfill all demandsperfectly.

Even the bearing points had to bechanged several times becausebefore approval they had to bechecked archeologically first. Now the visitor experiences acathedral like effect. If he stepsunder one of the big roofs he tonesdown his voice automatically andhe is behaving more respectful thanbefore. Where it was common to sit

on the temple ruins or to scratch atthem, the visitor becomes awondering observer.

The effect of the roof is veryprotective because the climateclose to the temples had changed.The very absorbent and soft limestone stays permanently dry now,because the salty rain brings nearlyno humidity to the stones.

The PTFE coated glass fabric filtersthe sun light and reduces its inten-sity to 10 to 15%. So the lime stonewalls are protected from the ultra-violet radiation, but can be lookedat with natural light conditions. It is also important that the textilecovering reduces the amplitudes of the stone temperature of 20°-70°-20°C considerably. Nowthe temperature value oscillatesonly in the range of the air tempera-ture.

ErectionAnother big challenge was theprotection of the excavation siteduring the construction period andthe restrictions involved. To protect the temples during theconstruction period they are neitherallowed to be trespassed nortouched. The use of big machines and ascaffolding was therefore notpossible. The complete cable and

membrane structure had to beassembled piece by piece byprofessional climbers - and the roofpanels were closed one after theother.

! Gerd Schmid: [email protected]: www.form-TL.de © Marco Ansaloni


Name of the project: Membrane roofs shelter stone-age temple, MaltaClient: Heritage Malta, MaltaArchitect: Walter Hunziker Architekten AG, BernPreliminary structural design, tender documents: Kiefer.Textile Architektur.Final structural design, membrane design, workshop drawings: formTL GmbHGeneral contractor: Canobbio Spa.Steel: MecoopCables: TeciAssembly: Montageservice SLCovered surface 1.495m² Hagar Qim/ 2.460m² MnajdraSpan central arch 54m Hagar Qim/ 68m MnajdraMaterial Membrane: Hagar Qim: PTFE-coated glass fabric SHEERFILL®II-HTMnajdra: PTFE-coated glass fabric SHEERFILL®I-HT

Fibrous and composite materials for civil engineering applications

Author: R. Fangueiro, University of Minho, PortugalLanguage: EnglishSize: 400 pages 234 x 156mm (hardback)Editor: Woodhead Publishing Limited (2011)

ISBN 1 84569 558 5ISBN-13: 978 1 84569 558 3

Content: PART 1 Types of fibrous textiles and structures; PART 2 Fibrous materials as a concrete reinforcement material; PART 3 Fibrous materials based composites for civil engineeringapplications.

Textiles, polymers and composites for buildingsAuthor: G. Pohl, Leichtbau Institut, GermanyLanguage: EnglishSize: 524 pages 234 x 156mm (hardback)Editor: Woodhead Publishing Limited (2010)

ISBN 1 84569 397 3ISBN-13: 978 1 84569 397 8

Content: PART 1 Main types of textiles and polymers used in building andconstruction; PART 2 Applications of textiles and polymers in construction.

LITERATURE


REPORT

4th Latin American Symposium Uruguay

Tensile Structures Montevideo 2011

Main LecturesFollowing the welcome address by the Dean ofthe Faculty and the introduction to the Sympo-sium by R. Santomauro, N. Goldsmith pre-sented “Skin. Biomembranes in buildings”.

After discussing natural skins, he went on totalk about building skins as holistic solutions inwhich the body and skin perform together, in-tegrating structure and environmental designconcepts. He used a series of case studies onthe work of FTL Design Engineering Studio (Fu-ture Tents LTD) to discuss several applicationsrelated to structure, form, acoustics, shading,lighting surface, energy generation, insulationand water collection that transform the notionof building facades into a porous multifunc-tional membrane reflecting the natural world.Special emphasis was placed on two textileroofs: the Sun Valley Pavilion (Fig. 1) for its dialogue between fabric and stone, and theSkysong at ASU Campus, Scottsdale, AZ (Fig. 2)for its dynamic rotational symmetry.

G. Schmid reminded the audience of the advan-tages of “ETFE” compared with glass in terms of

cost and maintenance based on transparency,spectral transmission, lightweight, stiffness,vapour barrier behaviour and thermal coeffi-cients. He also referred to the particularities ofcutting patterning, production and assemblyand emphasized the printing, colouring, lightingand self-cleaning capabilities together with recent applications in many fields that allowforward-looking architects to design their self-marketing envelopes (Fig. 3).The most frequently mentioned realization,with two main lectures and two presentations,was "La Plata Stadium" in Argentina (G. Castro,R. Ferreira, F. García Zúñiga, H. Larrotonda, M. Levy and T. Birdair), a derivative of the tensegrity Georgia Dome. Several speakers outlined the construction engineering, planningand procedures for the roof assembly, detailingthe cable net lifting, jacking system and membrane installation (Fig. 4).

In “Ejemplos en y desde Uruguay. Metodologíade trabajo”, P. Pinto and R. Santomauro pre-sented the Uruguayan state of the art with awealth of examples and a detailed descriptionof the entire process, from a simple primary

idea to the exact definition of the project, in-cluding all of the structural elements and theirdetails, the membrane, its patterns and its in-stallation on site (Fig. 5).

In “Lightweight structures and membranes forstadiums”, K. Stockhunsen from SBP insisted onthe design and installation of roofs for large-span applications. Worldwide developments inrecent decades culminate in the designs of thesports venues for the World Cup 2010 in SouthAfrica and the future icons of the BrazilianWorld Cup in 2014. Other impressive realiza-tions were presented from the Berlin OlympicStadium 2010 to the Warsaw National Stadium2012 and Rio de Janeiro Maracana Stadium2014 (Fig. 6).

C. Bauer from Mehler Tex•nologies began hispresentation “Tensile architecture. Principles offeasibility, sustainability and reliability in thepractice” with the Vitruvius principles (durabil-ity, utility and beauty) and summarized achronological development and possible futureevolutions. He described several aspects of tensile architecture as advantageous and

The “4th Latin American Symposium of Tensile Structures” was held inMontevideo in April 2011. It was organized by the Faculty of Architectureof the University of the Republic, Uruguay, and chaired by the architect R.Santomauro. It was the fourth in a series of symposiums that began in SãoPaulo in 2002, followed by Caracas in 2005 and Mexico D.F. in 2008.

Over three days, 11 lectures and 31 presentations were given to 278 participants from 19 countries and three continents. The main topics focused on recent projects, as well as new applications,basic concepts, features, materials, design, software, testing, installation and education.

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mentioned large spans, light conditions, economy (of time, energy and materials), effi-ciency, eye-catching forms, versatility, fire per-formance, uniqueness and cost (Fig. 7). Aspecial reference was made to sustainability,recycling systems and the need to rely on theright consultancy, specialist industry and prac-tical support. The Mehler TensileDraw availableat www.mehler-texnologies.com was recom-mended.

F. McCormick (Buro Happold) displayed insome detail the installation of the environmen-tally friendly 22.000m2 roof for the 80.000seat "2012 London Olympic Stadium". To pro-vide more potential for world records, complexCFD was used to analyse the wind regime onthe track and field, which revealed that a roofcovering will attenuate wind speeds. In addi-tion, the 28m high lighting towers were liftedon top of the inner ring in order to avoid dis-turbing photographers. These are new require-ments for contemporary stadiums that have tobe added to the FIFA demands for visibility ofthe advertising strip around the field and mayinvalidate most contemporary designs (Fig. 8).

A. Capasso presented “Membrane architecture:from research to teaching and realizations 40 years between the sails”, based on the re-search, teaching activities and realizations oflight structures that the author has carried outat the University of Naples’ Faculty of Architec-ture. Highlights of his career include the sails ofthe Triennale di Milano in 1973; Le tensostrut-ture a membrana per l’architettura, the firsthandbook on membrane structures in Europe in1993; the international conference "Architetturae leggerezza"; and the Laboratorio di Tecnologieleggere per l’ambiente costruito at the Universityof Naples, established in 2000. His current workinvolves university theses and research into de-veloping various functional and environmentalpossibilities for textile technology (Fig. 9).

J. Llorens lectured on “Detailing tensile struc-tures”, which form a substantial part of the de-sign process and influence the final result, butdo not yet form a well-known and well-docu-mented discipline. He presented a designmethodology for detailing tensile structuresbased on the principles governing their behav-iour and a prior recognition of the requirementsto be met, taking into account the characteris-tics of the project to which they belong. A typology was also illustrated by specific exam-ples placed in context that are available athttp://sites.upc.es/~www-ca1/cat/recerca/ten-silestruc/portada.html.

S. Delano and T. Dreyfus (Ferrari) in “Sustain-able development strategy in textile compos-ites” went into the material properties that arespecially suited for permanent installations,such as lightness, translucency and longevity.They furnished data on weight/m2, residual tensile strength (80% to 100%), exposition tosevere climatic conditions, energy savings byprotecting façades (more than 60% under theLatin American climate!), cost of recycling(~450 €/T) and life cycle analysis (Fig. 10).

In “Tensoestructuras. Diseños peruanos para elmundo”, A. Pérez and G.Carella presented awide variety of textile roofs designed or built byCidelsa, a Peruvian company that specializes

in architectural design and engineering, mem-brane transformation, high-frequency welding,manufacturing of steel structures and acces-sories, and assembly. The collection of projectsincluded shopping centres, stadiums, muse-ums, convention centres, beer gardens, squares,sports halls and stations (Fig. 11).

Current researchG. Filz from the Institute for Structure and De-sign (University of Innsbruck) presented in“Soft Spaces” his current research on anticlasticminimal surfaces that considers the infinitepossibilities of membrane forms as new ele-ments in architecture in combination withcommon building technologies that deliver newcapabilities in designing and creating space.

“Climatic Criteria for the Design of Tensile-Structures in Regions of the Humid Tropics” byJ.F. Flor dealt with the passive adaptation to theclimatic conditions of the humid tropic to ob-tain architectonic spaces that reach the maxi-mum hydrothermal comfort of users with theminimum resources.

In “Adaptable Structures”, R. Franco exploredmore than 20 mobile systems, aiming to applythe features of these systems to build and de-velop an adaptable architecture that satisfiesthe needs of the contemporary world.

P. von Krüger (Universidade Federal de MinasGerais) returned to the application of thetensegrity principles to latticed domes with as-sociated membranes as an active cover thatstretches the structure.

C. Morales (Universidad Veracruzana) based his“Design of Structural Flexible Systems in theArchitectural Space” on the understanding oforganic forms to construct a design methodol-ogy aimed at flexibility.

L. Moreira (Universidade Federal de MinasGerais), explored in “Form Finding of TensileStructures Made of Bamboo” the integration ofphysical and mathematical models.

Numerical methods were also present in “NewStrategies in Form Finding for Tensile Struc-tures” by F. Pantano (Uni Systems) and “TheNatural Force Density Method for the ShapeFinding of Membrane Structures” by R.M.Pauletti (Universidade de São Paulo).

Figure 1. Sun Valley Pavilion, Idaho, USAFigure 2. Skysong, ASU Campus, Scottsdale, AZ, USAFigure 3. Unilever façade , GermanyFigure 4. La Plata Stadium, ArgentinaFigure 5. Plaza Synergia, Zonamérica, Montevideo, UruguayFigure 6. National Stadium, Warsaw, PolandFigure 7. Harbin Sports Stadium, ChinaFigure 8. London Olympic Stadium lighting tower, UK Figure 9. Archetto. Espositore di vendita all’aperto, Napoli, ItalyFigure 10. Landfilling, incinerating or recycling?Figure 11. Estadio Municipal Lucio Fernandez Fariña, Quillota, Chile

REPORT

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Testing MethodsIn “Structural behaviour of textile roofs underdifferent climatic conditions”, C. Hernández(Instituto de Desarrollo Experimental de laConstrucción) showed the design of a testingapparatus and procedure for measuring the in-fluence of humidity, temperature and wind onthe pretension of hypars.

J.Blessman (Laboratório de Aerodinâmica dasConstruções, Rio Grande do Sul) was in chargeof the last presentation of the Symposium,which dealt with wind tunnel testing tech-niques.

Other presentationsSeveral Latin American countries were repre-sented and the latest realizations in Argentina(W. Runza and P.C. Valenzuela), Brazil (P.A.Barroso), Chile (O. Sotomayor) and México(J.G. Oliva, M. Ontiveros, V.H. Roldán and E.Valdez) were shown.

J. Monjo, representing H.Bögner-Balz forTensiNet, summarised the aims, objectivesand activities of the Association, which wasparticularly relevant because the Latin Ameri-can Network meeting was held afterwards.

EducationSeveral proposals and experiences for educa-tion were presented by leading professorsfrom Latin American institutions.

• J.G. Oliva Salinas: “Curso de ArquitecturaTextil”, 17 to 21 October 2011 plus 2months online, Universidad NacionalAutónoma de México. His experience wasdiscussed by P. Villanueva in the presenta-tion “Contemporary teaching of tensionstructures”, in which the online form findingof membrane structures “Membranes 24” isused (http://www.membranes24.com)

• J. Monjo: “Curso de Arquitectura Textil”2011/2012 (15 + 30 + 60 ECTS), UniversidadPolitécnica de Madrid. He discussed his ex-perience in the presentation “Teaching Ten-sile Structures”.

• Robert Wehdorn: “Membrane LightweightStructures”, Master Engineering Program(90 ECTS), Vienna University of Technology(http://mls.tuwien.ac.at).

• Unfortunately, Robert Off didn’t attend theSymposium to present his “Archineer andMaster of Engineering in Membrane Struc-tures”, Anhalt University of Applied Sciences, Dessau (http://www.membranestructures.de).

Software demonstrations (Fig. 12)In sessions parallel to the lectures and presen-tations, demonstrations of specific softwarefor designing tensile surface structures wereled by: Gerry d’Anza “ixForten 4000”(www.forten32.com); Dieter Ströbel “technet GmbH” (www.technet-gmbh.com) and Robert Wehdorn “Formfinder”(www.formfinder.at)

Exhibitors (Fig. 13)The exhibition of products in the main hall of the Faculty included Cidelsa(www.cidelsa.com), Ferrari (www.ferrari-architecture.com), ixForTen 4000 (www.forten32.com),Formfinder (www.formfinder.at), Makmax Birdair Taiyo Kogyo(www.makmax.com), Mehler (www.mehler-texnologies.com), Naizil SpA (www.naizil.com), Sobresaliente (www.sobresaliente.com), Synthesis–Gale Pacific (www.synthesisfab-rics.com), Verseidag (www.verseidag.de) and Wagg (www.wakk.com.ar).

Student competitionThe competition for design projects that makeuse of textile, cable or tensegrity structures,which was open to architecture and engineer-ing students, received 10 proposals. The jury,composed of J. Monjo, N. Goldsmith and G.D’Anza, awarded R. Vivar and J. Tataje for“Tensowrap: signals – protection – security” (Fig. 14).

Other activitiesT. Birdair offered the Welcome Cocktail, duringwhich music was provided by a sax quartet.The “criolla” Symposium dinner was the op-portunity to enjoy a Uruguayan meal. The cityof Montevideo was also worth visiting, partic-ularly the double-curved thin-walled shell insingle-thickness reinforced bricks by Eladio Di-este (Fig. 15).

Latin American Network of Tensile StructuresThe 4th Symposium was also the occasion tomeet the Latin American Network of TensileStructures. It assembled 60 participants withan interest in regional activities and envisagedthe collaboration or association withTensiNet. They decided to hold the next LatinAmerican Symposiums in Santiago de Chile in2012 and in São Paulo in 2014.

ConclusionThe Symposium ended with a panel discus-sion on tensile structures in Latin Americancountries, during which we learnt thatLatin American countries are not only fullyinvolved in the development of tensilestructures, but that they will also be veryactive in the coming years and constitute akey scenario for the future.

! Josep I. de Llorens : [email protected]: www.tens-mvd2011.org

Figure 15. Eladio Dieste Chapel

REPORT

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Figure 12. Software demonstrationFigure 13. Symposium exhibition Figure 14. Tensowrap” Winner of the student competition


ContextTransformation of a faceless site in Madrid’s urban sprawl,surrounded by industry and heavy traffic transportationinfrastructures, into a public space for social interaction providing abuilding for childcare (Fig. 1).

ProjectThe project “Plaza Ecopolis” aims to incorporate the idea of sustainabilityinto daily life. The main focus is therefore to create a vision of urbansustainability that facilitates the reduction of energy consumption bymatters of design but that also aims at raising people’s awareness of theirown consumption behaviour. The layout of the building generates a publicspace that can be used by the area’s residents, and it is considered as an“open environmental classroom”.Technologies implemented at Ecopolis project are helping the initial biocli-matic design approach based on minimizing the consumption of both energyand natural resources. The Ecopolis Plaza project has the highest eco-label (Agrade) of Spanish law. A complete energy simulation study developed by theThermodynamics Research Group at the Industrial Engineering School ofSeville, helps to understand the behaviour of the building and also to adjustthe available construction budget. An important area of the building half-buried (50% of the building takes advantage of the land’s thermal inertia)and a large glass facade facing south (700m²) are basic decisions that shapethe physical relationship between the building and its environment. A biocli-matic textile layer superimposed over a light steel structure is wraping the ra-tional concrete core of the building. This textile (partially movable, connectedwith sensors to sun position) is the interface between interior and exteriorspaces, blurring the boundaries between private and public and extendingthe inner comfort to the public space (Fig. 2).

The textile envelope is made of two kind of PES/PVC meshes: Ferrari Soltis86 and 92 in order to help view and solar control, and the final amount ofenergy coming inside the building (Fig. 3). The zeroclastic surfaces drainrainfall due to the mesh porosity, but needed to be designed with highprestress loads in order to prevent damages due to snow and wind loads.The building extends its limits into the plaza and part of its functionalprocesses are placed outside to make them more transparent to the public,creating a more conscious way of wasting natural resources. The sewagesystem ends into a lagoon in front of the building where all the waste waterfrom the building is naturally purified by macrophyte plants. All the purifiedwater is stored under the ground within a gravel tank and it is used for all theirrigation needs of the plaza, this artificial landscape emulates a naturalriverbank.Ecopolis Plaza is also a demonstrative experience of economy of meansapplied to the field of sustainable construction, where efficiency usuallymeans higher construction cost. The Ecopolis project cost per square meteris more than 35% less than a conventional building.

! Javier Tejera, José Javier Bataller, Marian Marco: [email protected]: www.batspain.com ! José Luis Vallejo, Belinda Tato: www.ecosistemaurbano.com

Additional information: http://inhabitat.com/

madrids-sustainable-ecopolis-plaza-is-a-versatile-public-space/

TEXTILE WRAPA SUSTAINABLE CONSTRUCTION

Ecopolis Plaza,Madrid, Spain

BAT SPAIN - ECOSISTEMA URBANO

Name of the project: Ecopolis PlazaLocation address: Rivas Vaciamadrid, MadridClient: Rivas CouncilFunction of building: EducationalType of application of the membrane: Textile Roof And FacadeYear of construction: 2011Architects: Ecosistemaurbano, José Luis Vallejo, Belinda TatoTextile Engineering: Javier Tejera, José Javier Bataller, Marian Marco - Bat SpainMain contractor: HMContractor for the membrane (Tensile membrane contractor): Bat SpainSupplier of the membrane material: FerrariManufacture and installation: Bat SpainCovered surface (roofed area): 1500m2

Figure 1. Aerial view of the Ecopolis Plaza

Figure 2. Textile as the interface between interior and exterior spaces

Figure 3. Connection detail

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The international student competition „Textile Structures for NewBuilding“ was held for the 11th time in 2011. As with the previouscompetitions, a review of this year’s competition is certainly cause forcelebration. The large number of entries from many countries and thehigh standard of work submitted confirm that the competition istaking the correct approach. Held for the first time in 1993, the competition aims to promote construction using textiles. The objective is to awaken the interest and enthusiasm of students fora method of construction which offers great potential for innovationand a wealth of opportunities for enriching the world of architecture asa whole. It is the students of today who will work with textiles anddesign the textile buildings of the future. As tomorrow’s architects,they will have a great influence on the appearance of our urbanlandscape. It is therefore important to promote their work and to give them the opportunity to work with new materials. The entriessubmitted provide impressive evidence of the opportunities offered by construction using textiles. A total of 12 projects received a prize.

Organizers: Techtextil, Messe Frankfurt and TensiNet AssociationJury: Nasrine Seraji (France -Chairwoman of the Jury),

Heidrun Bogner-Balz (Germany), Gert Eilbracht, (Austria), Alex Heslop (U.K.), HG Merz (Germany) and Werner Sobek (Germany)

The TensiNet Association sponsors this International StudentCompetition.

As in previous years, the jury awarded prizes in four categories:

Category 1: Macro Architecture 2 Awards1ste PRIZE: Plusminus Pneumatic Gridshell (Sebastian Kron, Nora

Haase-Aschoff, Mathias Hackmann, Philipp Kuner,Julian Lutz, Fabian Pfeiffer)

2nd PRIZE: Tensegrity Ring (Diana Maritza Peña Villamil)

Category 2: Micro Architecture 3 Awards1ste PRIZE: X-Change (Riva Fleur Vidal)1ste PRIZE: TS-1 textile selfsupporting (Andreas Moog)1ste PRIZE: Knitecture (Stefanie Powell)

Category 3: Sustainability and Surface 3 Awards 1ste PRIZE: KnitSkin (Annelie Asam, Sally Alejos)2nd PRIZE: FLOW (Thorsten Klaus)3th PRIZE: Double Layered Membrane (Elena Vlasceanu)

Category 4: Composites and Hybrid Structures 2 Awards2nd PRIZE: Monotex (Viktoria Darenberg, Leonard Chmielewski)2nd PRIZE: Sound Adaptive Acoustic System

(Mohammad Mustafa Kadiri)

In addition, two further prizes were awarded which were not related toany specific category. Honorable Mention

Textile Wall (Lisa Spengler, Moa Hallgren)Wandering Championships (Tomasz Kujawski)

Prof. Dr.-Ing. Werner Sobek

INTERNATIONAL "TEXTILE STRUCTURE FOR NEW BUILDING 2011” COMPETITION FOR STUDENTS AT TECHTEXTIL

Figure 1. Category 1: Macro Architecture "Plusminus Pneumatic Gridshell" 1ste Prize

Figure 2. Pavilion of Student Competition1 2

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