The latest news magazine from the GroupIssue 38 · November 2011 · 15th year [22nd English translation]

Gigantic Terrafix® mats havebeen combined with traditionalwillow bundles (fascines) in order to solve one of the mosturgent problems of the Elbe River near Cuxhaven.Between Cuxhaven and Otterndorfis an area called "Altenbrucher Bogen", literally the "Altenbruchbend". There, the Elbe River curvesand the navigable water extendsespecially far from the shore. Thestrong currents in this area havecaused continuous erosion to theshore. The natural mudflats havereceded significantly in recent years, threatening the dike.

Furthering this waterway chal-lenge, plans have been set in motion to deepen the navigable water. Greater depth will enableeasy passage for large containerships regardless of the tide andimprove access to Hamburg Har-bour. This alteration of the wa-terway, if not addressed in im-proved shoreline engineering,would further increase the flowspeed and cause additional prob-lems for the dike and mudflats.

The solution for this dilemma hasbeen found through the utiliza-tion of highly engineered, mod-ern geotextiles and traditionalfascines.

Officials from Lower Saxony andthe Federal Water and Ship As-sociation developed the conceptfor this permanent and secureshore protection plan. The coreof the idea consists of 24 groynesextending into the Elbe Riveralong the Altenbrucher Bogen to keep the river from eroding the ground further. The groynesof this ongoing project are being

constructed up to 250m long and are being placed along the bend, covering an area of approx-imately 3km.

Filter mats for base protectionAbove the water line, the groynesappear to be the same as tradi-tional stone breakwaters. Thespecial characteristics that definethese groynes are hidden under-water, beneath the foundation:Large geosynthetic revetmentmats, in combination with woodfascines, not only prevent tidalerosion but promote sand depo-sition.

Each of the special underwatermats are assembled on site and measure 30m x 70m. NAUE Terrafix® geotextile panels areunrolled next to one another atthe shore and sewn together toachieve the desired size. Terrafix®773 G43, a multilayer staple fibrenonwoven geotextile mat, hasbeen selected for its performanceand durability in coastline ero-sion prevention applications.

For the Altenbrucher Bogen area,the Terrafix® panels are needle-punched to a fabric layerequipped with loops. Ropes,which tightly bind the woodyfascines to the geotextile, arepulled through the loops. Thefascines consist of numerous willow rods bound into longround bundles several metreslong. The fascines are fastenedto the Terrafix® at a right angle,lengthwise and crosswise, spacedabout 1m apart.

Tugboats, then, pull the fascinemattresses into position. Smallrocks weight the fascine mattresses

as they are lowered. Next, the actual groynes are built up usinglarger breakwater stone.

The groynes and fascine mat-tresses now provide mutual pro-tection. The rocks hold the mat-tresses in place. The nonwovenfabric prevents erosion of the waterway bed. The fascine pat-tern promotes sedimentation.This creates shallow water areaswith sand deposits between thegroynes. It also makes those areasaccessible and able to be used forleisure activities. The project isnot yet complete, with a final

phase planned for 2012. In total,it covers an area of 200,000sqmand is considered one of thelargest water construction zonesin Germany. The executors,"ARGE Buhnenbau Otterndorf",are comprised of the companiesHeinrich Hirdes, Colcrete von Essen, Johann Bunte and Van denHerik. Essential support has alsobeen provided by the CuxhavenWater and Shipping Authority.

By the end of the project, approx.220,000sqm of Terrafix® 773 G43and approx. 30,000sqm Terrafix®B813 will have been installed.

The year 2011 will godown in history as anextraordinary year —for the world and alsofor NAUE. Significantrevolutions in Tunisia,Egypt and Libya oc-cured, while in several nations protests andriots challenged otherlong-time rulers. Theseevents have left manydead and injured.

In March, the massiveearthquake in Japanand its subsequent tsunami led to themeltdown of a majornuclear facility in Fu-kushima. Thousands ofpeople were killed androughly 150,000 wereforced to leave theirhomes due to radio-active contamination.These shocking events

have unfolded alongside pro-tracted economic concerns inthe United States (the world’slargest economy) and financialbailouts in Greece that are nowprompting larger discussionsabout the euro’s strength.

Despite these dramatic humanand political events and the per-sistent uncertainty in financialmarkets, the real economy inmany parts of Europe has actu-ally not been hampered. The lowest unemployment rate sincethe reunification in Germany isone indication that in manyparts of the world economies are succeeding. Record sales in Germankey industries such as automotive and engineeringprovide further proof. Also, the NAUE Group expects a new sales record to be achievedin 2011. Our manufacturingcenters are running at full capacity; and the current order

backlog suggests a strong firstquarter for 2012. We are partic-ularly pleased that this situationapplies to our new productionfacility in Malaysia. As reportedin the last NAUE News, we opened a Bentofix® Geosyn-thetic Clay Liner (GCL) manu-facturing center in April 2011in Selangor, about an hour'sdrive from Kuala Lumpur.

In its first 9 months of opera-tion, the plant has produced materials for numerous success-ful construction projects inAustralia and Asian countries.

The Selangor factory is certifiedby TÜV Nord in accordance with ISO 9001, meaning ourcustomers receive the same security and quality from theplant in Malaysia as they expect and receive on the otherside of the world in our Germanplants.

So we are well-positioned towork with our products to meetthe application challenges of thefuture, such as strengthening en-vironmental protection systems,developing better transport in-frastructures, and providingsafer, more sustainable systemsfor flood protection, coastal ero-sion control, and offshore windturbine scour protection.

Questions remain, however, as towhat extent the current debt andfinancial crises in various countriesand banks will have on global eco-nomic stability. The uncertaintyaffects more than just the con-struction industry; in an intercon-nected world, it affects everyone.We can only hope that the recentlyannounced measures to combatdebt in Greece and to the rescueof the euro will be successful.We want to thank all our custom-ers and suppliers for their coope-ration and trust during what

has been for the world in generala challenging year. And we wantto thank all of the NAUE Group’semployees for their continued dedication. We wish all readers a Merry Christmas and a HappyNew Year, and we hope for a morepeaceful 2012.

Double Re-Design for the A1 near Didžiulio Lake, Lithuania

Time crunch under the floor bridge

Road Building over Peat in Canada

Safety for sand bunkers and ponds

Capping and Revegetating a Class IIMSW Landfill in Langenlonsheim, Germany

Success vs. Sinking in Brunei

Further information:www.naue.com

CONTENT

Terrafix® and willow bundles stabilise groynes in the Elbe River

Elaborate coast protection efforts at Altenbrucher Bogen

NAUE TV releases new films

Technical films focus on geosyn-thetics and their applications

“Construction of the new A8Highway with Secugrid®”, “The SafeCoast” and “The Safe Landfill” arejust a few of several film titles onour NAUE website (www.naue.com).Each film profiles and explains cer-tain geosynthetics, their advantagesand exemplary uses.

The high-definition, high-quality mov-ies show installations and appli-cations with NAUE geosynthetics. Stereoscopic computer animationshelp explain key functions and construction methods.

An easy-to-use menu bar appears onthe bottom of your screen and helpsput you in control, allowing you tochange the volume, stop, fast for-ward, rewind and zoom.

We invite you to view our online movies and affiliated documentation at any time via the web addresswww.naue.tv.

Did you know…?2011 – a historical challenging year!

For the modernisation and ex-tension of Lithuania’s busy A1 Vilnius-Klaipėda roadwayproject, a major embankmentneeded to be widened to accom-modate larger vehicles and in-creased traffic volumes.

The project designer, Kelprojek-tas, identified the need for geogrid reinforcement of thisembankment early on. Somediscussion was given to the po-tential need for added erosion

protection along the lake-abut-ting slope in one area of theconstruction. The region re-ceives a regularly high amountof precipitation.

With the slope being exposed to this precipitation during construction and the immediatepost-construction period, morestringent erosion control wasthought to be the best idea.However, the project directorsinitially selected the lowest cost

design, which involved only thereinforcement. It was a decisionthey would soon reverse.

The utilisation of Secugrid® 40/40 Q6 geogrids allowed theslope-enlargement design to bebuilt at a 1:1 incline, which was needed for the most securefootprint immediately adjacentto the lake. Also, the embank-ment had to be built to 6m inheight. Construction went asplanned, with reinforcementlayers installed horizontallyevery 0.8m. A wrap-around, orenvelope, method of geogridplacement was used.

In the middle of this summerinstallation, shortly before theslopes were completed, a suddenintense rainfall brought about a change in the design.

The precipitation caused signif-icant washout of the clayey-sandy soils, affecting the newlylaid roadway surface and some

slope zones leading down to thewater. The original design sug-gestions were revisited and thistime the installation of erosioncontrol matting was approved.

The project team chose Secu-mat®, a robust, three-dimen-sional erosion control mat witha UV-stabilised polymer core,able to withstand environmentalexposure. This complex, durablematrix controls surface erosionand helps to anchor and rein-force the root zone of plants.

After the erosion-affected soilswere replaced and compactedand all Secugrid® soil wrappingswere confirmed as secure, rollsof Secumat® were installed onthe slopes and anchored to thetop of the slope.

The erosion control matting was then pinned into place us-ing steel pins. Soil and seedwere then added on top of the Secumat®.

Before the next summer seasonarrived, the roadway was fullyopen and vegetation was sprou-ting along the waterside slopes.

It’s hard to make a roadwayblend into the natural environ-ment, but the newly greenedembankments along Vilnius’s

beautiful Didžiulio Lake havesucceeded making this revi-talised, busy road pleasant todrive along.

How can tunnel construction beadvanced at the same time asthe inner shell is being finished,when enormous amounts of material must be moved past thesensitive sealing locations? Thesolution: a “floor bridge.” Thisconstruction is used to carry offmaterial during tunnel advance-ment. The floor is built up underthe bridge layer by layer. Spaceis limited and it requires exacttiming in the execution.

The Reitersberg Tunnel will be a 2975m long section of the new high-speed railway betweenNuremberg and Erfurt in Germany. The tunnel is beingbuilt near Rödental in NorthernBavaria and will cost approxi-mately 100 million euros.

The double-shell tunnel requiressealing against pressurised water.A geosynthetic lining system isutilised here. Water must not penetrate and substances harmfulto the environment must nottrickle into the surrounding rockformations. The maximum waterpressure is 45m above the tunnelfloor. NAUE geosynthetics are being installed to form the mul-tilayer sealing system, which consists of Carbofol® tunnelgeomembrane, Carbofol® water-stops and Secutex® protectionnonwoven geotextiles.

The greatest challenge of the Reitersberg project has been en-suring a flawless installation ona tight timeline. The welding ofthese critical waterproofing pan-els is a difficult operation due to the space constraints and site-specific tunnel geometry. But the geosynthetic system must be

welded properly to ensure thematerials provide the high levelof function for which they havebeen engineered: a service life of at least 100 years. NAUE Seal-ing’s deeply experienced expertshave been brought in to guaran-tee the professional execution of the tunnel liner installation.

NAUE Sealing is a STUVA e.V.-certified professional installer.(STUVA e.V. is the research association for underground traffic installations.)

Exact timing under the floor bridgeThe Reitersberg Tunnel has beenopened from both sides by meansof explosives and excavators. As work progresses, the rock issecured and sealed and the innershell of reinforced concrete is installed. Allowing it all to happen efficiently is the tunnel’sunique “floor bridge.”

The floor bridge, a 100m longstructure, allows the inner tunnelshell to be dug out under it. Thisis done section by section. Underthe floor bridge, three sectionsare staged and the complex innershell is put up in six phases:

1. Bottom road bed excavation and massive material removal under the floor bridge.2. Securing by means of steel support arches, mesh rein- forcement, and anchors and shot-crete. The latter also serves as a carrying layer for the sealing material. 3. Installation of the sealing system. 4. Reinforcement of the floor with bars and mesh.

5. Concreting the 60 to 90cm thick inner shell of reinforced concrete in the inverted arch. 6. Finishing of the full layer of the inverted arch / floor zone concrete.

As highlighted in this list, thefloor area requires numerous in-stallation steps. Each step in-volves coordinating workers froma variety of disciplines in tightspaces, all the while carrying offlarge amounts of material along-side other critical tunnel work.

This method of constructionavoids a significant amount ofthe idle time that is normally required in tunnel construction,but it requires extraordinary cooperation and communicationby the project team.

Strong planning before the projecthas prevented the interface prob-lems that might otherwise have occurred, and as the project hasprogressed each discipline of spe-cialist has learned more about theothers—boding well for future util-isation of this construction method.

Sealing against water pressure The geosynthetic sealing liner system being used in the Reiters-berg Tunnel consists of a protec-tion nonwoven geotextile, a geo-membrane, and a geosyntheticwater stop system. For both thefloor and vault seals, the geo-membrane is installed from a mov-able scaffolding, which has beentailored specifically for the geo-metry and work needs of the site.

The nonwoven geotextile Secu-tex® has a site-specific minimummass of 900g/m². Approximately

Double Re-Design for the A1 near Didžiulio Lake, Lithuania

2

Exhibition and seminar schedules

150,000sqm have been installed.Secutex® is a needle-punched geotextile that protects the tunnel waterproofing liner frommechanical damage.

The Carbofol® tunnel geomem-brane has a thickness of 3mm.The roughly 150,000sqm of geo-membrane must be placed by ex-perienced professionals because

the overlapping seams must be100% waterproof. Sealing expertsand construction supervisionteams test each seam for tightness

by means of pressurised air. TheCarbofol® tunnel liner is coatedwhite on the side facing into thetunnel, which makes any poten-tial installation damage more easily visible. It also allows morelight to the working area, as thelight reflects off the surface ofthe white liner. This increasedvisibility further helps increasethe quality of the panel seaming.

External six-stud Carbofol® wa-terstops seal the joints of eachlined tunnel section. A total of approximately 13,000  running

metres of water stops are beingused. In the floor zone, a second3mm thick Carbofol® layer (as protection geomembrane) ofapproximately 50,000sqm havebeen placed above the primarysealing tunnel geomembrane.

Construction began in 2009. Thetunnel breakthrough was cele-brated on 21 July 2011, and the

goal is to complete theinner shell by mid 2012.By 2017, the first trainswill be able to use thenew track. DB Netz AGis the builder responsiblefor this project. The jointventure ARGE Rödental-Reitersbergtunnel, con-sisting of the construc-tion firms Alfred KunzUntertagebau and Swie-telsky Tunnelbau, is lea-ding the construction.

NAUE is proud to haveits products utilized in

the work, and NAUE Sealing is proud to be part of the expertinstallation crew on site.

15. - 17.12.11 Indian Geotechnical Conference IGC-2011 Kochi, Kerala, India

20. - 24.02.12 8th International Conference on Coastal and Chennai, India Port Engineering in Developing Countries, PIANC-COPEDEC VIII

08. – 10.03.12 Acqua Alta Alpina Salzburg, Austria

25. - 29.03.12 GeoCongress 2012 Oakland, California

23. - 27.04.12 Hannover Messe Hanover, Germany

24. - 28.04.12 38th International Building Trade Fair SEEBBE Belgrade, Serbia

02. - 05.05.12 GeoAmericas Lima, Peru

07. - 11.05.12 IFAT 2012 Munich, Germany

31.05. - 02.06.12 12th Baltic Sea Geotechnical Conference Rostock, Germany

Time crunch under the floor bridgeAdvancing and sealing at the same time in the Reitersberg Tunnel

Sand bunkers and ponds are notthe most inviting sections of acourse for golfers, but for coursedesigners, club pros and main-tenance crews, these obstaclesdemand a great degree of careand attention. Geosyntheticsplay an important role in keep-ing these expected but unpopu-lar hazards “in play”.

Golfing has grown significantlyas a global sport in the past 25years, and this has led to manynew courses being constructed.The increased number of courseshas meant that many are nowbuilt atop sites with difficult soils.Bunkers and ponds present spe-cial challenges on these courses,and not just for the players.

NAUE’s portfolio contains solu-tions that are uncomplicated,quick and easy to install. Theseproducts and systems help mod-ern course construction meettheir needs for stable, dependableplay. Of note, Bentofix® geosyn-thetic clay liners (GCLs) provideideal containment for ponds and

Terrafix® nonwoven mats keepbunkers dry and free of stonesand coarse soil.

Hydraulic engineering for bunkersTerrafix® is a robust, permanentsolution for hydraulic engineer-ing in golf course sand traps. The nonwoven mat provides essential separation and drain-age – both of which are requiredfor reliable bunker playability.The highly engineered non-woven component of Terrafix®allows stormwater or irrigationwater to drain through todrainage channels while simul-

taneously serving as a durableseparation layer between the subsoil and bunker. The sandused in the traps is generally ofa special nature and often rep-resents a significant investmentfor course managers. That sandshould be protected from subsoilmixing and the humidity that thesubsoil can add to the sand whenwater does not flow through. Terrafix® provides those key per-formance solutions. Course play-ers will be especially thankful for soft, dry sand and for neverencountering a stone that hasmixed into the sand from the

subsoil. Geosynthetic drainageand separation maximizes theperformance of your trap.

The power of powder: bentonite,GCLs, and pondsGolfers commonly lose strokesand golf balls in course ponds,but for the site owner thoseponds can be the source of aes-thetically unpleasant water lossand high maintenance costs. Toensure the proper function ofponds as both visually attrac-tive (albeit challenging) hazardsfor golfers and active collec-tion basins for course drainageand water management, NAUEBentofix® geosynthetic clay lin-ers (GCLs) provide an exceptionalseal. The needle-punched GCLsare reinforced composites thatcombine two durable geotextileouter layers and a uniform coreof high-swelling powderedsodium bentonite clay. When hy-drated with fresh water, the ben-tonite swells and forms a lowpermeability gel layer that saveswater in the pond. The sealingpower in Bentofix® is in fact so

significant that it is utilized notjust for the economical sealingof golf course ponds but for en-gineered barrier systems withlevees, reservoirs, landfill caps,and many other applications.

Additional solutionsBunkers and ponds are not theonly areas on a course in whichgeosynthetics are used. Specialgeotechnical challenges may befound with slopes or ditches, access roads, parking lots, retain-ing walls, etc. NAUE’s completeline of geosynthetic solutionshelp bridge the gap between

common and unique problems incourse construction and success-ful, long-term course perfor-mance. The use of geosyntheticsin new construction or restoredgolf courses is cost-effective andlowers the overall costs enor-mously. Geosynthetics can be quick andeasy to install, and they help sig-nificantly reduce the long-termmaintenance (and high mainte-nance costs) associated with golfsites. Built with NAUE’s tech-nologies, courses drain better,ponds hold their water, and dis-parate soils remain separated.

Ontario’s Highway 62 runsthrough numerous swampy areas. Significant stretches ofthe road, like the province it-self, overlie peaty soils. Prop-erly maintaining roads in these areas has historically been difficult due to issues of set-tlement, which have led tosubgrade breakdowns androadway cracking and failures.

For a stretch of Hwy 62 southof Bancroft, the Ontario Min-istry of Transportation, workingwith design engineering firmGolder Associates, sought a separation, reinforcement anddrainage/filtration solution that

would address and counter thetypical problems of road build-ing over the area’s peat.

Project engineers selected Combigrid® 30/30 Q1 151-1composite geogrids for road-way reinforcement. This uniqueproduct from NAUE is composed of not just a high-strength geogrid (Secugrid®) but a needle-

punched nonwoven geotextile(Secutex®) — all in a single ma-terial.

This is the only composite prod-uct of its type in the market.Rather than installing an indi-

vidual geotextile and a geogridlayer, the site crews needed onlyto install Combigrid®, whichfeatures the nonwoven geotex-tile firmly welded between the Secugrid®'s reinforcement bars. In one layer, soil stabilisation,separation and filtration/drainage is provided. For weaksoils such as those with a CBRvalue less than 3%, the solution

is ideal. This held true alongHwy 62. The selection of themultifunctional Combigrid®saved the project team time and money on installation whileensuring the long-term strengthand performance desired in the

Road Building over Peat in Canada

3

Safety for sand bunkers and pondsGolf courses have high requirements

project. Combigrid® allowed for a shallow excavation (to thepeat depth) and easy reconstruc-tion. The reinforcing element reduced the need for excessiveaggregate and the geotextilecomponent ensured no mixingof disparate subgrade material.Ultimately, the pavement struc-ture was able to be constructedas thin and lightweight and eco-nomically as possible withoutsacrificing roadway integrity.The risk of differential settle-

ment was dramatically reduced.Also of note: the wide Combi-grid® rolls helped reduce wasteon site and expedite construc-tion. Only two rolls of productwere needed to cover the entireroadway reinforcement width aswell as provide a 12in. overlapfor maximum assurance of coverage and long-term strength.

During construction, one lanewas reinforced at a time whilethe other was left open to traffic.

The composite geogrid rollswere unrolled in place and covered quickly to reopen thelane as soon as possible.

Roughly 10,000sqm (107,600 sq. ft.) of Combigrid® 30/30 Q1 151-1 were installed.

For Highway 62’s commuters, a smoother ride has been pro-vided, and it’ll be there for along time.

Did you know…?In May 2011, the new, 70 MW Sălbatica II wind farm in Romania served as an interesting test site for NAUE Combigrid® 30/30 Q1 151 GRK 3. (A larger profile of the wind farm itself was featured in the July 2011 issue of NAUE News.)

Combigrid® was installed for the base course reinforcement on soft subsoils to create a stable platform for the Liebherr 750t cranes that were used to erect the wind turbines, each of which was composed of several

heavy segments.

To scale the tensile strength in the grid and the loading pressureunder the reinforced working platform, strain gauges were appliedon the Combigrid® layer and on load-bearing measurement plates inthe subsoil under the reinforcement. These tools enabled the collectionof exact stress conditions in the geogrid and in the reinforced basecourse during different stages of the construction process.

The goal of this data collection has been to verify or optimise theperformance of existing designs for the dimensioning of reinforcedcrane working platforms in the field.

The analyses have been elaborated on by Prof. Eng. Loretta BataliPh.D.(Technical University of Civil Engineering, Bucharest) and aPh.D. student. The student is steadily tracking this subject with the support of NAUE GmbH & Co. KG and BBG Bauberatung Geokunststoffe GmbH & Co. KG.

Up until 2003, residentialwaste was disposed of in the municipal solid waste(MSW) landfill in the dis-trict of Langenlonsheim.With the site needing to becapped as part of waste cellclosure operations, NAUESealing has been retained to provide single-sourcesupport. The company is de-livering and installing theessential geosynthetic com-ponents: NAUE Bentofix®,Carbofol®, Secudrain® and,where the slopes are steep-est, Secugrid®.

As the crow flies, this MSW siteis located 1.5km southwest ofthe Waldlaubersheim exit of the A-61 motorway. The wastedisposal organisation (Abfall-wirtschaftsbetrieb AWB) of thedistrict of Bad Kreuznach mustcomplete the municipal wastecell capping in accordance withthe regulations covering Class IIlandfills and recultivate the en-tire surface of the former landfill.A part of the measure consistsof the controlled catching anddraining of stormwater andleachate from the landfill massand, in connection with the seal-ing, capture of landfill gases.

Above an equalisation and drainage layer, the landfill capconsists mainly of:- NAUE Bentofix® NSP 4900 geosynthetic clay liner with the German LAGA suitability assessment.- NAUE Carbofol® 507 2.5mm Megafriction/Megafriction high-density polyethylene (HDPE) geomembrane with BAM certification- NAUE Secudrain® R201Z WD601Z R201Z geocompos- ite drainage layer with BAM certification- Vegetation

Installed as the bottom-mostlayer, Bentofix® NSP 4900 is, at

its core, a barrier layer of pow-dered sodium bentonite thatswells immediately when itcomes into contact with waterand thereby seals against gasesand liquids. The bentonite is en-capsulated between two high-strength, highly durable, needle-punched geotextiles.

In accordance with the regula-tions for Class II landfills, MSWlandfills must also have a sec-ond liner. For Langenlonsheim,the second liner consists of the2.5mm thick HDPE Carbofol®507 geomembrane. The surfaceof the membrane is textured onboth sides. To expedite con-struction, the Carbofol® panelsare welded together on-site directly after unrolling and positioning. Atop the geomem-brane, NAUE Secudrain® geo-composites are installed for protection and drainage/gasventing management.

The Secudrain® R201Z WD601ZR201Z is a compound materialmade of filtering geotextiles thatare linked to each other in ashear-proof manner and aroundpolymeric drainage core. Land-fill capping is a typical applica-tion of use for the Secudrain®line of products. The product is a protection mat, a filtering mat and a drainage mat all in

one, which makes it possible toinstall it quickly and economi-cally.

In sections that are steeper, thelandfill embankments will be reinforced additionally with Secugrid® 80/20 R 6. The geogrid will be installed directlyon Secudrain® and will securethe topsoil that is brought in.

NAUE Sealing GmbH & Co. KG’sBückeburg, Germany office re-ceived the order for the Langen-losheim site in part due to thecompany’s extensive experienceand strong reputation for instal-lation quality. The combinedservice of delivering the highlyengineered NAUE geosyntheticsfor the projects was also key inwinning the project.

The overall task of sealing the50,000sqm waste area andrecultivating the surface is inthe hands of the Langenlons-heim Landfill Working Group(Arbeitsgemeinschaft Deponie),which consists of the construc-tion companies Hermanns HTIBau GmbH & Co. KG and theBickhardt Bau AG. The con-struction will take more thantwo years.

The geosynthetic installation onsite began in September 2011.

4

Success vs. Sinking in Brunei

Capping and Revegetating aClass II MSW Landfill in

Langenlonsheim, GermanyGeosynthetic separation and re-inforcement materials are engi-neered for ground modificationand improvement applications.One of the most common appli-cations is base course stabiliza-tion in roads. As traffic loadspass over the roadway, the ten-sile forces can cause crackingand rutting as the pumping ac-tion induced beneath the surfacecauses fines and coarser aggre-gate to mix.

A separation geotextile preventsthose aggregate layers frommixing. A reinforcement geo-grid redistributes those tensileforces and interlocks with theaggregate to prevent lateral mi-gration. In both cases, roadwayservice lives are extended, per-formance improved and stan-dard maintenance greatly re-duced.

Active roadways, however, arenot the only installations thatmight require these functionsfrom geosynthetics. Many con-struction projects themselves re-quire separation and reinforce-ment geosynthetics to supportthe construction activities, suchas when work is performed overweak soils and heavy equipmentis used.

This need was exemplified by aproject in Brunei. During theconstruction of an interchange,multiple cranes were placed onsite to handle various aspects ofthe construction, such as borepiles and materials movementfor piling and bridge construc-tion. The area experiencedheavy rains during constructionoperations, rains which not onlydelayed general site work butcaused significant erosion. Oneof the cranes sank and toppledwhen it ventured too close tothe unreinforced edge (see bot-tom picture).When the project team investi-gated the sunken crane, they

discovered that the reinforce-ment and separation geosyn-thetic installed beneath the stag-ing area had not been extendedfar enough. Two of the primarycranes were unaffected becauseof the geosynthetic beneaththem. The third crane was situ-ated upon only the weak soil,and when enough soil washedout from beneath it and whatremained was saturated the soilmodulus became too weak tosupport the crane.

Shortcuts Lead to a Longer RoadBrunei’s soft soils are primarilycomposed of sandy, silty clayswith high montmorillonite con-tent or silty, peat soils. Annualprecipitation is up to 1500mm(59in.). This often requires mul-tiple geosynthetics to enable safe, heavy construction.

For the project site that experi-enced the collapse of one of itscranes due to weakened soils, aunique geosynthetic had beenspecified. Manufactured by NAUE GmbH & Co. KG, the Combigrid® product providesboth a separation geotextile anda reinforcement geogrid in a single-layer product that cansimply be unrolled into position.

The needlepunched nonwovenlayer is secured in the material

during the manufacturing pro-cess and is sandwiched betweenthe transverse and longitudinal high-strength geogrid monolithicbars. This allows the product toprovide reinforcement, as well as filtration, separation anddrainage functions.

On site, the geosynthetic-sup-ported zone experienced someerosion, but the base moduluswas held in tact by the geogrid.Water penetrating the soil wasable to drain through the geo-textile, which also provided separation to prevent mixing. The cranes were supported.

Where the Combigrid® had notbeen installed, the base course on which the crane was stand-ing mixed with the subbase andthe platform basically sunk. Also the water washed out thesoil and both this caused thecrane to topple.

With one storm and one photo-graph, we find an essential lessonabout geosynthetic utilization depicted clearly. Not only canseparation and reinforcementgeosynthetics provide moredurable and more economicalroadways, but the constructionprocess itself can be made moreefficient and less subject to disruption.

The information contained herein is the best to our knowledge, true and accurate. There is no implied or expressed warranty. ©2011 by NAUE GmbH & Co. KG, Espelkamp-Fiestel, Germany · All rights reserved.Editor: Management. Implementation: Department for Marketing. Circulation: 2000, Design/Production: TwoTypes². Bahnhofstr. 14, 32312 Lübbecke, Germany. Reproduction, including extracts, may only be made with the prior permission of the publisher.