January - April 2003

reyssinet

Rescuing a historic structure

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JANUARY/APRIL 2003 - No. 216

Rescuing a historic structure

Netherla

24 higsecurp. 16

Interview

“Specialist services”p. 4C

on

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tsContents

2Freyssinet magazine January/April 2003 - n° 216

ARGENTINAFreyssinet-Tierra Armada S.A.Buenos AiresPhone: (54.11) 43 72 72 91Fax: (54.11) 43 72 51 79

BRAZILSTUP Premoldados LtdaSão PauloPhone: (55.11) 3873 2734Fax: (55.11) 3672 8502

Freyssinet LtdaRio de JaneiroPhone: (55.21) 2221 8500Fax: (55.21) 3852 7926

Terra Armada LtdaRio de JaneiroPhone: (55.21) 2233 7353Fax: (55.21) 2263 4842

CANADAReinforced Earth Company LtdMississaugaPhone: (1.905) 564 08 96Fax: (1.905) 564 26 09

COLOMBIASTUP de Colombia LtdaBogotaPhone: (57.1) 236 3786Fax: (57.1) 610 38 98

Tierra ArmadaBogotaPhone: (57.1) 236 37 86Fax: (57.1) 610 38 98

EL SALVADORFessic S.A. de C.V. La LibertadPhone: (503) 2 78 86 03Fax: (503) 2 78 04 45

GUATEMALAPresforzados Técnicos S.A.Guatemala CityPhone: (502) 2204 236Fax: (502) 250 01 50

MEXICOFreyssinet de Mexico S.A.Mexico D.F.Phone: (52.55) 5250 70 00Fax: (52.55) 5255 01 65

Tierra Armada S.A. México D.F.Phone: (52.55) 5250 1726Fax: (52.55) 5254 8665

UNITED STATESFreyssinet LLC Chantilly, VA Phone: (1.703) 378 25 00Fax: (1.703) 378 27 00

Ménard Soiltreatement Inc.Orange, CA Phone: (1.714) 288 84 47Fax: (1.714) 639 87 01

The Reinforced Earth CompanyVienna, VA Phone: (1.703) 821 11 75Fax: (1.703) 821 18 15

VENEZUELATierra Armada CaCaracasPhone: (58.212) 266 47 21Fax: (58.212) 267 14 23

BELGIUMFreyssinet Belgium N.V.VilvoordePhone: (32.2) 252 07 40Fax: (32.2) 252 24 43

Terre Armée Belgium VilvoordePhone: (32.2) 252 43 24Fax: (32.2) 252 24 43

DENMARKA/S SkandinaviskSpaendbetonVaerlosePhone: (45.44) 35 08 11Fax: (45.44) 35 08 10

FINLANDOY Jaennebetoni Helsingfors

FRANCEFreyssinet International & CieVélizyPhone: (33.1) 46 01 84 84Fax: (33.1) 46 01 85 85

Freyssinet FranceVélizyPhone: (33.1) 46 01 84 84Fax: (33.1) 46 01 85 85

PPCSaint-RémyPhone: (33.3) 85 42 15 15Fax: (33.3) 85 42 15 10

Terre Armée FranceVélizyPhone: (33.1) 46 01 84 84Fax: (33.1) 46 01 85 85

Ménard SoltraitementNozayPhone: (33.1) 69 01 37 38Fax: (33.1) 69 01 75 05

FYROMFreyssinet BalkansSkopjePhone: (389.2) 118 549Fax: (389.2) 118 549

GREECEFreyssinet Hellas S.A.AthenaPhone: (30.10) 69 29 419Fax: (30.10) 69 14 339

Fredra S.A.AthenaPhone: (30.10) 69 29 419Fax: (30.10) 69 14 339

HUNGARYPannon Freyssinet LtdBudapestPhone: (36.1) 209 1510Fax: (36.1) 209 15 10

IRELANDReinforced Earth Co.KildarePhone: (353) 4543 10 88Fax: (353) 4543 31 45

ITALYFreyssinet - Terra ArmataS.r.lRomaPhone: (39.06) 418 771Fax: (39.06) 418 77201

NETHERLANDSFreyssinet Nederland B.V.WaddinxveenPhone: (31.18) 26 30 888Fax: (31.18) 26 30 152

Terre Armée B.V.BredaPhone: (31.76) 531 93 32Fax: (31.76) 531 99 43

NORWAYA/S Skandinavisk Spennbetong SnarøyaPhone: (47.67) 53 91 74

POLANDFreyssinet Polska Sp. z o.o.MilanòwekPhone: (48.22) 724 6893Fax: (48.22) 724 68 93

PORTUGALArmol-Freyssinet S.A.LisbonPhone: (351.21) 716 1675Fax: (351.21) 716 4051

Terra Armada LtdaLisbonPhone: (351.21) 716 1675Fax: (351.21) 716 4051

ROMANIAFreyrom S.A.BucarestPhone: (40.21) 220 28 28Fax: (40.21) 220 45 41

SPAINFreyssinet S.A.MadridPhone: (34.91) 323 95 00Fax: (34.91) 323 95 51

Tierra Armada S.A.MadridPhone: (34.91) 323 95 00Fax: (34.91) 323 95 11

SWEDENAB Skandinavisk SpaennbetongMalmöPhone: (46.40) 98 14 00

SWITZERLANDFreyssinet S.A. MoudonPhone: (41.21) 905 09 05Fax: (41.21) 905 09 09

UNITED KINGDOMFreyssinet LtdTelfordPhone: (44) 1952 201 901Fax: (44) 1952 201 753

Reinforced Earth Company LtdTelfordPhone: (44) 1952 201 901Fax: (44) 1952 201 753

TURKEYFreysasIstanbulPhone: (90.216) 349 87 75 Fax: (90.216) 349 63 75

Reinforced Earth Company AIS IstanbulPhone: (90.216) 492 8424Fax: (90.216) 492 3306

Ireland

56 stay cables to crossthe Boyne Riverp. 15

EUROPE

Freyssinet Magazine, 1 bis, rue du Petit-Clamart 78148 Vélizy Cedex – France. Phone: +33 1 46 01 85 40. Fax: +33 1 46 01 86 86. Internet: www.freyssinet.comPublication manager: Claude Lascols. Project leader: Stéphane Tourneur. Contributed to this issue: PhilippeAmiot, Isabelle Angot, Amaya Arrondo, Krzysztof Berger, François Bignon, Samuel Briet, Bill Brockbank, LaureCéleste, Stéphane Cognon, Jean-Philippe Fuzier, Zoran Gapic, Bertrand Garin, Albert Gilles, Michelle Haynes, AnikJean, Roger Lacroix, Salvador Lorente, Paul McBarron, Jan de Meyer, Albert Moizeau, Sylviane Mullenberg, PatrickNagle, Tomas Palomares, Susana Penas, Bertrand Petit, Jim Preston, Chris Robinson, Pierre Salanne, Pierre Sery,Alain Tigoulet, Martin Van Den Berg. Layout: Pierre Bonnerre. Translation: Netword. Editorial secretariat: AngelineBlard. Photos: Francis Vigouroux, Freyssinet photolibrary and subsidiaries. Cover page: Agen footbridge, photo:Francis Vigouroux. Photo-engraving: Trameway/Pierre Bonnerre. Printing: SIO. ISSN: 1636-4112.

AFRICAEGYPT

Freyssinet EgyptGisaPhone: (20 2) 303 69 95Fax: (20 2) 345 52 37

SOUTH AFRICA

Freyssinet Posten Pty LtdOlifantsfonteinPhone: (27.11) 316 21 74Fax: (27.11) 316 29 18

Reinforced Earth Pty LtdJohannesburgPhone: (27.11) 726 6180Fax: (27.11) 726 5908

Although Freyssinet makes every effort to supply the most precise possible information, the publishers and their employeesor agents cannot guarantee that this information is accurate and cannot accept any responsibility if it is not. Names printedin italics in this brochure are registered trademarks of the Freyssinet Group.

AMERICA

Romania

40 000 m2 consoliand drainedp. 12

United States

“Vibro-replacement”for earthquake resistancep. 19

Contents


ASIA

HONG KONGFreyssinet Hong Kong LtdKowloon TongPhone: (852) 27 94 03 22Fax: (852) 23 38 32 64Reinforced Earth Pacific LtdKowloon TongPhone: (852) 27 823 163Fax: (852) 23 325 521

INDIAReinforced Earth-Aimil LtdNew DelhiPhone: (91.11) 695 00 01Fax: (91.11) 695 00 11

INDONESIAPT Freyssinet TotalTechnologyJakartaPhone: (62.21) 830 02 22Fax: (62.21) 830 98 41

JAPANF.K.K. TokyoPhone: (81.3) 35 71 86 51Fax: (81.3) 35 74 07 10

KUWAITFreyssinet International et CieSafatPhone: (965) 571 49 74Fax: (965) 573 57 48

MALAYSIAFreyssinet PSC (M) Sdn BhdKuala LumpurPhone: (60.3) 79 82 85 99 Fax: (60.3) 79 81 55 30

Ménard Geosystems Sdn BhdSelangorPhone: (60.3) 5632 1581Fax: (60.3) 5632 1582

Reinforced Earth ManagementServices Sdn BhdKuala LumpurPhone: (60.3) 6274 6162Fax: (60.3) 6274 7212

PAKISTAN Freyssinet - Reinforced Earth Pvt LtdIslamabadPhone: (92.51) 2270 443Fax: (92.51) 2270 445

PHILIPPINES Freyssinet Philippines S.A. Quezon CityPhone: (63.2) 921 3789 Fax: (63.2) 921 1223

OCEANIA

AUSTRALIAAustress Freyssinet Pty LtdSeven HillsPhone: (61.2) 9674 40 44Fax: (61.2) 9674 59 67

Austress Freyssinet (VIC)Pty LtdMelbournePhone: (61.3) 9326 58 85Fax: (61.3) 9326 89 96

Reinforced Earth Pty LtdHornsbyPhone: (61.2) 9910 9910Fax: (61.2) 9910 9999

NEW ZEALANDReinforced Earth LtdAucklandPhone: (64) 9 236 33 85Fax: (64) 9 236 33 85

Freyssinet New Zealand LtdAucklandPhone: (64) 9 236 33 85Fax: (64) 9 236 33 85

Poland

“Incremental launching” as a

solution in extremesituations!

p. 20

Hong Kong

Kwai Chung Terminal 4

p. 17

ands

gh ity houses

6

Australia

U beams exported to

Tasmania!p. 14

SINGAPOREPSC Freyssinet (S) Pte LtdSingaporePhone: (65.6) 272 96 97Fax: (65.6) 272 38 80

Reinforced Earth Pte LtdSingaporePhone: (65.6) 272 00 35Fax: (65.6) 276 93 53

SOUTH KOREAFreyssinet Korea Co, LtdSeoulPhone: (82.2) 2056 05 00Fax: (82.2) 515 41 85

Sangjee Ménard Co LtdSeoulPhone: (82.2) 587 9286Fax: (82.2) 587 9285

TAIWANFreyssinet Taiwan EngineeringTaïpeiPhone: (886.2) 274 702 77Fax: (886.2) 276 650 58

THAILANDFreyssinet Thailand LtdBangkokPhone: (662) 266 6088Fax: (662) 266 6091

UNITED ARAB EMIRATESFreyssinet Middle East LLCAbu DhabiPhone: (971) 2 445 88 18Fax: (971) 2 445 88 16

VIETNAMFreyssinet International et CieHanoiPhone: (84.4) 826 14 16Fax: (84.4) 826 11 18

France

TerraTrel walls with natural rock appearancep. 23

Macedonia

A strategic route rescued from the waterp. 18

dated

Portugal

Computer aidedrenovationp.17

Spain

Concrete for a cut and cover tunnelp. 23

”

France

Express repair!p. 22

France

Rescuing a historicstructure

p. 8

Interview

4Freyssinet magazine Janvier/Avril 2003 - n° 216

Strategy

Freyssinet Magazine: You definethe Freyssinet Group’s services asbeing specialist services. What doyou mean by that?

Bruno Dupety: Our objective is simply tobe the best in all our specialties, which incudeconstruction, repair and maintenance of struc-tures, and improvement and reinforcement ofsoils. Best performance means that we will doeverything necessary in each of our specialtiesto have the superior expertise, quality andinnovation. Let us be clear about this: we usu-ally work on projects with major stakes interms of safety, reliability, technical and eco-nomic performances and durability. When weapply prestressing for a tall building, or installstay cables for some of the largest bridges in theworld, or build retaining walls for dozens ofbridges along a motorway segment, when weconsolidate several hectares of ground for theconstruction of a shopping center or an indus-trial site, we must accept a major responsibilityand make a long term commitment. This istrue for major projects, and is equally true for

“Specialist services”Freyssinet for structures, Terre Armée and Ménard Soltraitement for soils, are recognised international leaders in their specialties.Technological progress made by the Freyssinet Group, augmented by many innovations and motivated by an ambitious research and development policy, enables it to optimize the globalperformances of its achievements, particularly in terms of durability.

more modest projects. This is why, we do thebest we can to provide the specialist's optimumsolution to satisfy clients, engineers and maincontractors who expect us to provide elegantsolutions to their problems. Obviously, thisspecialist approach does not prevent synergiesbetween our teams and companies before theproject starts. Scientific and technical coopera-tion, mutual enrichment of skills and exchangeof experience are all deeply rooted in our cul-ture. Our intellectual is spread throughout ournetwork of almost seventy offices in the world,with the support of our transverse services,such that a project carried out on any one con-tinent will benefit the group's global expertise.

How is this quality requirementthat you mention established?

In each of our specialties, we commit ourselvesto meeting high performance criteria that arespecified and known to our customers, andwhich are usually stricter than standards ingeneral use in the construction sector.Obviously this quality question concerns our

Bruno Dupety, CEO of the Freyssinet Group“We are doing everything necessary to keep our expertise,quality and innovation at the highest possible level.”

5Freyssinet magazine Janvier/Avril 2003 - n° 216

Interview

products, most of which are developed andtested in our own laboratories, but it is equallyapplicable to installation, respect for deadlinesand durability. Regardless of the aspect con-cerned, such as the minimum strength of mate-rials, the behaviour of stay cables during age-ing, settlement performance of a site, and soon, the purpose of this requirement is alwaysthe same, namely to provide customers withthe best possible quality and performance.Many of our projects have become are interna-tional structural and geotechnical references,and clearly demonstrate the success of thisapproach.

You tell us that technical expertisecontributes to global optimizationof a project. Could you give ussome examples?

Boyne bridge, the first cable stayed bridge inIreland, is a good example of performance intechnical terms and for optimization of dead-lines. Although we arrived on this project as asubstitute, we succeeded in mobilizing ourindustrial resources and our site teams toinstall 56 stay cables with 37 to 73 strands, rep-resenting 360 tonnes of steel, in less than onemonth at the end of 2002. It was a significantadvantage that we manufactured our staycables and anchors ourselves.In the field of soil improvement, the futureA380 Airbus manufacturing site on a 1320000 m2

area in Hamburg illustrates the advantages ofour exclusive Ménard Vacuum process. Thiscombines technical performance, ease of useand competitiveness, by considerably reducingconsolidation times and also achievingunequalled reliability.In mechanically stabilized embankments andprecast arches Reinforced Earth companies areleaders as a result of continuous efforts to

introduce and improve exclusive products. Wehave recently developed new metal ladderswhich significantly reduce the cost per m2 forlow structures. We have also developed specialsoftware and control our own production toolsthat are used to develop cladding on which agenuine architectural expression is possible inthat each element forms part of a pattern. Asan example an aquarium now forms part of thelandscape on a motorway in the United States.

Innovation has always been a tradi-tion within the group. What is yourpolicy in this field and what is themost important recent progress?

Our research and development policy is basedon three themes. Firstly, improvement of ourexisting technologies. For example, in staycables, there are new vibration dampingdevices and high performance carbon fibrecables (installed for the first time on Laroinfootbridge in France), these two innovationscontributing to improving the durability ofbridges, in prestressing, improvements to ourrange of anchors in order to reduce weight andprovide a more compact cable, which is there-fore also more economic, in soil improvement,development of bottom feed stone columnsunder air pressure for offshore work.The second theme applies to new ideas thatreach us from the market and that we improvewith our own expertise, usually in cooperationwith manufacturers. This is how we developeda carbon fiber fabric in recent years for thereinforcement of concrete structures, and morerecently the Régébeton process for which wewere awarded second prize in the building /public works category of the 2002 Siemenscompetition. This process consists of applyingan electrolytic paste to eliminate chlorides that

corrode concrete while protecting the originalwalls, thus preventing major reconstructionwork. This category also includes monitoringand preventive maintenance systems for civilengineering structures, that we have helped todevelop as part of our research on increasingthe life of structures.Finally, there are some radically new ideas thatare very different from current practice. Youwill understand that I cannot talk about thistype of research in detail. I will simply mentionthat our group has expanded and developedthrough major inventions, such as strand bystrand stay cables in the Freyssinet system,dynamic compaction and vacuum compactionconsolidation techniques used by MénardSoltraitement and the Reinforced Earth systemthat has revolutionized construction tech-niques for retaining walls and bridge abut-ments. Our collection of 140 patents is a sign ofthis continuous technological progress that hasbeen continuous throughout our history, andmore than ever before we intend to continuethis policy!

Carbon fibre cables, installed on the Laroin footbridge in France, contribute to improving the durability of structures.

For retaining walls, “we are developing cladding onwhich a genuine architectural pattern is possible”.

Venezuela Mexico

New Internet site

The managers of the Petróleos deVenezuela Anónimos company (PIDVSA)decided to build a sports complex on the heights of the town of Los Teques in the state of Miranda in Venezuela, forthe employees of its INTEVEP subsidiary,which specializes in research anddevelopment of new technologies in the oil and gas industry. The topography of the selected site was steep and broken.Reinforced Earth technology was thereforechosen for construction of a foundationsurface about 15 m thick with a totalvertical surface area of 1 030 m2.The process enabled the project to be completed within a short time and before the planned date!

The Tahiti Development Authority and its technical consultants decided to use Reinforced Earth technology to construct walls for the approaches,as part of the development of the RiverPunaruu interchange viaduct close toPapeete. The surface area of the walls was 1 000 m2, and their maximum height 7.30 m. The walls are parallel andTerre Armée France therefore proposedthe use of Freyssisol reinforcement usingthe “back to back” technique, to connectthe two sides of the ramp to each other.The Terre Armée Company designed and supplied the wall surfaces, providedthe moulds for precasting the surfaceelements, and also provided technicalassistance for precasting and assemblingthe foundation blocks.

In brief

Freyssinet magazine 6 January/April 2003 - n° 216

The Freyssinet Group is opening its new Internet site.This site will be updated regularly, and will be a rich source

of information about the Group's latest news and its history, its offices and plants, and all its activities.

Enjoy your browsing on http://www.freyssinet.com !

Walls for INTEVEP

Tahiti

Freyssisol near Papeete

Concrete canoes… using TFCAfter a year's hard work, the group of seventeenstudents of the Faculty of Engineering at UNAM(Independent National University of Mexico),the prizewinner of the first national competitionfor concrete canoes, were rewarded for theirefforts - by winning the right to representMexico in the National Concrete CanoesChampionship, alongside 260 other universities!This competition was organized in Madison,in Wisconsin, in the United States, and wassponsored by the American Concrete Instituteand Master Builders Technologies. This project combines research, architecture andconstruction and is based on the development

of concrete techniques and other innovativematerials. The manufactured canoes had to pass a floatation test and participated in several races.Freyssinet Mexico helped the students to make their Puma canoe, which required four preliminarydesigns to optimize its weight, stability,hydrodynamics and aesthetics. The students choseto strengthen their canoe using carbon fibers fabric(TFC) technique developed by Freyssinet, due tothe flexibility of its two-directional reinforcementcapable of matching the shape of the structure. ThePuma canoe earned a respectable place in the finalclassification at this event, in which Mexico wasparticipating for the first time, arriving in 25th place.

In brief

7 January/April 2003 - n° 216Freyssinet magazine

South Africa

Sea Cow lake is north of the city of Durban in South Africa. It is about one kilometer from the Umgeni river that supplies water to the 5 million inhabitants in the Durban district.Although this marshy region is close to the citycentre, it is almost completely undeveloped andit is still a breeding ground for fish eagles andfor many other marsh birds. However, things are changing, and a new industrial centre isbeing built. Its promoters have worked closelywith the authorities to define a project includingthe construction of several infrastructures.These include a nine-span bridge now underconstruction to cross the river, the railway andthe alluvial plain. Freyssinet Posten, the Group'sSouth African subsidiary, was asked to work on this part of the project. The cast in situprestressed concrete deck is 400 m long and uses110 t of longitudinal and transverse prestressingcables. Freyssinet multi-strand systems wereused for the construction of this first bridge.Another post-tensioned bridge called the “N2overpass” crosses the existing national road withits access ramps, and is now under constructionby incremental launching. Freyssinet Posten is responsible for supplying and installing theprestressing. The N2 overpass will consume an additional 115 t of prestressing cable.Apart from these two bridges, the developmentprogram for the zone includes a service station, industrial buildings and a prestressedconcrete bridge providing access to them.When this work is finished, the promoter willrestore the marsh to its original condition… in other words, like it was a century ago, beforeman first explored it. There are even plans to reintroduce hippopotami!

A bridge over the marshes

Spain

Tierra Armada, Freyssinet's subsidiary in Spain, worked on phase II of themotorway bypass project for the town of Las Palmas in the Canary Islands.Tierra Armada designed and supplied all materials for construction of theabutments with a total surface area of 3 600 m2. These 24 m high and

40 m wide structures are among the tallestever built.

ParticipantsClient: Canary Islands MotorwayEngineer: Necso-Ferrovial Joint VentureSpecialised contractor: Tierra Armada S.A.

Since the middle of 2002, the Morgan-Vinci Joint Venture has been working on the construction of the NewportSouthern Distributor Road (SDR).The work package for soil treatment in port areas and the adjacent tip was awarded to Ménard Soltraitement.The soil on this site consists of a 10 to 12 m thick layer of poor quality alluvials,above which lies a heterogeneous andoccasionally polluted fill material. Thereis a layer of gravels under the alluvials,with a consistency varying from dense to very dense. Apart from pollution in some areas, there is a large number of cable networks and pipes that makethe project more complex. MénardSoltraitement installed a network of

more than 7 000 Controlled ModulusColumns (CMC) 10 to 16 m long, toimprove the soil and make it capable of supporting 2 to 9 m thick road fill.At the moment, two CMC machines are working on soil treatment ofabout 1.5 km of road. Columns areconventionally anchored into the hardlayer by 1 m, over most of the site area.However the environmental constraintsat the tip are very restrictive.For example, the columns cannot pass through the alluvial clays.The chosen grid is therefore much denser and expected settlements areslightly greater. The CMC techniqueshould be used again, further along the line of the road.

Record abutment heights on the motorway

Wales

More than 7 000 controlled modulus columns

France

Main characteristics:

• First construction date: 1839• Bridge length: 263 m• Deck width: 2.30 m• Tower height: 20 m• Number of suspension cables: 2• Number of hangers: 88di

gest

France


More than 150 years after it wasbuilt, Agen footbridge had becometoo hazardous fo r i t s users .

After several hesita-tions between destruc-tion and restoration,Freyssinet proposed a compromise solu-

tion. A story of a repair from bot-tom to top.

digest

The solution proposed by Freyssinetconsists of replacing the suspension,and the tower and deck cable anchors.This is a seventeen-month project.

Rescuing a historicstructure

Agen footbridge

France

10 January/April 2003 - n° 216

Steeped in history…

AGEN BRIDGE WAS BUILT IN 1839 TO CROSS THE

Garonne and form a link between the townof Passage and the city of Agen. Its length of263 m makes it one of the longest suspendedfootbridges in France.Its first suspension used chains. This systemwas replaced by steel wires in 1883, 1894, andthen in 1936. The existing structure com-prises five spans, including three 29.5 m,174.25 m and 20.6 m long suspension spans.The 2.30 m wide deck is a metal structurewith wood decking. The suspension cablesare supported on saddles fixed on 18 m highmasonry towers. Two access spans on the leftbank are constructed of lattice girders.

… but dangerous

The footbridge was completely closed in 1997, due to aging of the structure and a number of structural problems(dynamic loads could not be resisted satisfactorily due to the slenderness ofthe deck). However, after loud protests from its users, the structure was opened tothe public again under very strict condi-tions; no more than fifteen persons at atime on the deck, closure of the bridgewhenever the wind speed is higher than45 km/h. At the same time, design workwas started on a solution for a new unsus-pended footbridge.

Destroy or restore?

The announcement of the end of thisfamiliar landmark in Agen was the subjectof many local discussions. But Freyssinethad already had the opportunity to dosome maintenance work on the foot-

bridge, and finally convinced the clientthat a rescue was possible.Therefore, a call for bids was issued in1999 to repair the structure, and to main-tain operating conditions of the formerfootbridge.This call for bids was unsuccessful, and soanother call for bids was issued the fol-lowing year; Freyssinet was awarded thecontract based on an alternative solution.

An almost entirely new structure…

In the proposed solution, the suspension,cable anchors, towers and the deck had tobe restored to new condition, and the sus-pended access spans had to be replaced by simple lattice girders. This projectrequired seventeen months of hard work!The old masonry towers built in 1841 werethen dismantled stone by stone andreplaced by two 20 m high steel masts,hinged at the bottom, and to which thesaddles were fixed. These new shafts werefounded on micro-piles drilled throughthe bottom of the masonry piers.The suspension was replaced by two60 mm diameter galvanized suspensioncables, to which eighty-eight V hangerswere fixed, each consisting of a 16 mmdiameter cable anchored on cross-girdersof the deck.Furthermore, in order to improve thestructural behaviour of the suspensionspan (particularly for resistance to windand transverse stability), transverse cableswere provided similar to the cables pro-vided for the Tours footbridge over theCher (magazine No. 210). These fourcables are fixed onto new anchor founda-tions fixed to the ground by active tie-rods.The lateral cables are associated with thetriangulated suspension, and apply a pre-load to it. Finally, the assembly forms amore stable and also less flexible structurethan a traditional suspension system, andthis arrangement makes new footbridgeusers feel safer and more comfortable.The new installed deck consists of twobeams made of steel profiles connectedtogether by cross-girders parts. This con-figuration maintains the appearance ofslenderness and lightweight that charac-terized the old structure. The deck wasconstructed using tropical hardwood.The new deck was installed on top of theold deck, and the new structure was thenused to dismantle the old structure.The work was completed at the end ofDecember 2002.

Freyssinet magazine

France


… perfectly consistent with history and the site

The general form of the new footbridgeis generally similar to the original,although its structure is much moremodern, and the local population unani-mously appreciates it. The “La Passerelle”Association offered a stone block takenfrom the old towers to Freyssinet duringthe inauguration ceremony.

Participants

Client: Town of AgenEngineer: EEG SimecsolArchitect: Stéphane BrassieMain contractor: Freyssinet

Suspension verticale

Suspension triangulée

Nouvelle suspension avecdes suspentes triangulées et descâbles de stabilisation latéraux

775

533

338

Comparative study of deformation under concentrated load

Vertical suspension

Triangulated suspension

New suspension with triangulated hangers andlateral stabilizing cables.


Romania

In August 2002, Ménard Soltraitement was awarded soil improvementand depollution work under the area to be occupied by a future Corahypermarket to the East of Bucharest, in Romania.

Cora hypermarket

A LARGE AMOUNT OF SOIL IMPROVEMENT

and depollution work was necessaryon the site on which the future

hypermarket will be built. The area to betreated (40 000 m2) occupies part of the siteof former brickworks that used sand andgravel present in the soil. The brickworkshad excavated a pit 150 m wide by 450 mlong with a depth of up to 16 m. This exca-vation was then used to deposit urbanwaste, and was then filled with inert mate-rials so that a precast concrete elementplant could be constructed and operateduntil 1990.

Soil improvement: between stone piers and stone columns

A deep foundation solution on piles was initially envisaged due to the poorquality of the fill, and the building would then have been supported entirely by abeam and slab system. The alternative soil improvement solution proposed byMénard Soltraitement was based on surfacefoundations and slabs on grade. The depthof the ground to be treated (up to 16 m)was the reason for choosing a hybrid solu-tion combining the stone piers and stonecolumns techniques.The stone piers are an extrapolation ofdynamic compaction in which the ram-ming energy is used to form large columns(2 to 2.5 m diameter) of compacted granu-lar material by “dynamic substitution”.These inclusions will then support surfacefoundations of the building and the slabson grade.

40 000 m2 consolidatedand drained

bearing capacity, if they are compacted atdepth.

4 months of almost uninterrupted work

The work was completed in four months,due to the use of two stone columnmachines equipped with 12 m and 18 mvibrating needles and compaction crane,at a working rate of 24 h per day and6 d/week. Eventually, more than 5 220stone columns were completed at an aver-age depth of 15 m, with 750 stone piersand 800 compaction impressions.

Depollution by ventilation

Once the foundation problem had beendealt with, the bio-gas problem had to besolved. Household waste was still decom-posing in the fill, and the accumulation of these decomposition gases (mainlymethane), under the slab on grade creates aserious risk of spontaneous explosion.The solution proposed by MénardSoltraitement based on the “venting” tech-nique, is exactly the same as that used onthe Stade de France (in Paris outskirts).This technique consists of circulating a sufficient quantity of fresh air in theground to be depolluted, to dilute decom-position gases to reach a concentrationthreshold per unit volume low enough tobe sure that they are not noxious (for risksof deflagration or poisoning). The result-ing gases (noxious gases and fresh air fordilution) can thus be released into theatmosphere.

However, the maximum possible treatmentdepth using this technique cannot exceed7 m for energies usually used. Therefore, itwas necessary to use stone columns to rein-force the soil at depth in the most criticalareas (in other words in areas in which thedepth of the existing uncompacted fill isgreater than this treatment depth).The load distribution induced by the piersgives a good stress distribution at the top of the columns. Furthermore, the sur-rounding ground provides better lateralrestraint on the columns, essential for high


Romania

14 000 m of fresh air and intake drains

This dilution is achieved by installing anetwork of drains in a layer of drainingmaterials. The system comprises firstly a network of intake drains connectedthrough header pipes to a pumping stationin which a negative pressure is created inthese drains, and secondly a network offresh air drains connected to the atmo-sphere through header pipes.The air is routed as follows. It is drawn outof the atmosphere into the ground (underthe slab on grade) through the fresh airdrains network; it passes through the soiluntil it reaches the intake drain network, inwhich it is mixed with noxious gases; thegas mix then passes through the headerpipes of the intake network as far as thepumping house, and is then released intothe atmosphere.The entire system is sized such that dilu-tion is below allowable limit at all times(allowing for a safety factor).These networks will be installed under thefuture building (40 000 m2) and will have atotal length of about 14 000 m of drains(63 mm diameter) and 5 600 m of headerpipes (160 mm diameter). They should be laid early in 2003 before the slab ongrade is poured, over a period of about twomonths.

Participants

Client: CORAEngineer: IBTMain contractor: Hervé Romania SrlSpecialised contractor: Ménard Soltraitement

Principal plan showing the degassing network


Australia

Austress Freyssinet is participating in the reconstruction of the Sorell road bridge-jetty in Tasmania: a first in Australia.

Sorell Causeway road bridge

T HE SORELL CAUSEWAY ROAD BRIDGE IS A

strategic part of the Tasmania road net-work. This bridge forms part of the

Tasman Highway and is located at the easternend between Pittwater Bluff and MidwayPoint, 20 km east of Hobart in the south of Tasmania. The bridge was finished in1957, and at the time was the largest pre-stressed bridge in Australia. Due to increas-ingly severe signs of structural deteriora-tion reducing its carrying capacity, theDepartment of Infrastructure Energy andResources (DIER) decided to replace thebridge as soon as possible, in order toincrease the total allowable load on it.Therefore, the new structure will be a U-beam composed of prefabricated segmentsbased on the concept developed in France byFreyssinet and Jean Muller International.This concept has only been used in France(where Freyssinet has built several bridges forroad development authorities) and in NorthAmerica, so the Sorell Causeway bridge willbe the first of this type in Australia.

U beams exported to Tasmania!

Optimise the use of prefabricated elements

The contract deals with two separate workpackages. Work package A covered an 18-month design and construction period forthe new bridge and its accesses. Package Bwhich began after the new structure was putinto service, is for demolition of the oldbridge and construction of launching slipsfor emergency service boats . The contractwas awarded on July 19 2001. Work packageA was completed on January 19 2003, andthe end of the project is programmed forJuly 19 2003. Prefabricated elements arecomposed of a very compact concrete toresist the marine environment. The prefabri-cation site was installed on an unused area4 km from the site. Austress Freyssinet pro-vided technical assistance and supervisionfor this site, specifically for fixing the rein-forcing cage and for installing cable ductsaccording to the specified tolerance require-ments. The bridge consists of two 1200 mmdeep box-girders. The U-beam segmentswere launched from the previous span, andfixed with epoxy glue and temporary pre-stressing. Permanent partial prestressing was applied and the entire span assemblyjacked into position and lowered onto thepermanent bearings. Final prestressing wasthen applied and the launching beam movedonto the next span. The segments were pre-stressed longitudinally and transversely.

Participants

Client: Department of Infrastructure Energy and Resources Tasmanian GovernmentEngineer: John Holland Pty LtdConsultant: GHD Pty LtdSpecialised Contractor: Austress Freyssinet(VIC) Pty Ltd

Freyssinet is responsible for specialised prestressing

John Holland Pty Ltd designed and con-structed bridge No. 1 and its accesses, demol-ished the existing structure, and all the aux-iliary work defined in the specification. JohnHolland used Austress Freyssinet's knowhow in prestressing, for technical advice andconstruction techniques. John Holland wasawarded the contract for prefabrication ofthe segments and for prestressing of theU beam, including a total of eighteen 25.5 mspans. The consultant for the design workwas GHD, and Austress Freyssinet Pty Ltdwas involved as the prestressing consultantduring the design phase.


Freyssinet Limited participated in construction of the bridge over the Boyne. This is now the largest bridge and the first cablestayed bridge in Ireland.

Ireland

T HE BOYNE BRIDGE CARRIES PART OF THE

new motorway under constructionbetween Dublin and Belfast. When it is

put into service at the end of 2003, this willbe the first toll motorway in Ireland. A jointventure formed by the Irish Contractor SiacCompany, and the English Cleveland BridgeCompany was appointed to build this 170 mmain span cablestayed bridge. Aninverted Y towersupports the deckusing 56 Freyssinetstay cables com-prising between 37and 73 strandseach. The hybriddeck is made ofbox-girders madeof steel, support-ing a concrete sur-face layer.Freyssinet Limitedwas awarded the contract for the supply andinstallation of stay cables in March 2002.Fast mobilization was a compulsory require-ment, and within six weeks Freyssinet hadinstalled the first pair of stay cables necessaryto stabilize the tower so that the group couldstart launching the deck.

360 tonnes of strands

Freyssinet placed the 56 stay cables in thestructure, including 360 tonnes of strands,between September and the end of November

2002. Freyssinet Limited worked in closecooperation with the Freyssinet InternationalMajor Projects Department for engineeringaspects, the methodology and procurement.The Boyne bridge clearly shows the advan-tages of Freyssinet stay cables and the effi-ciency of work done in cooperation betweenFreyssinet, the contractor and the engineer.

The essential char-acteristics of theFreyssinet systeminclude fast mobi-lization and higherection speed, flex-ibility and ease ofadaptation to Grouprequirements, adap-tation to the project,flexibility and effi-ciency of its plant,and experience andquality of all per-sonnel.

Participants

Client: NRA (National Roads Administration)/Meath County CouncilEngineer: Roughan & O’Donovan ConsultingEngineersPrime contractor: CoentrepriseSiac / ClevelandBridge Joint VentureStay cables: Freyssinet Limited

Bridge over the Boyne

56 stay cables tocross the Boyne River

T HE TOWN OF DEN BOSCH IN HOLLAND

decided to convert the West bank ofthe town into a clean, high security,

and outstandingly beautiful area. As aresult, Fortis Vastgoed Ontwikkeling N.V.carried out the construction of 24 luxuri-ous villas in keeping with these values, onthe former Concordia football field. Fourunits of six houses each were constructedon this site, and garden-terraces are siteddirectly on the lakefront behind the hous-es. The terrace walls are stabilized by rein-forced earth walls. Three islands forleisure will also be built in the lake andwill eventually be linked to dry landthrough footbridges.

Between TerraClass and TerraTrel

Two types of walls were selected to stabilizethe sides. 500 m2 of TerraClass walls and1000 m2 of TerraTrel walls were built in eightweeks of work and the end result is impres-sive. The walls were built at a batter of 10°from the vertical for aesthetic reasons.Cruciform shaped TerraClass elements wereused on the topsoil, up to an elevation of26 cm above the lake level. A TerraTrel latticewall system was installed on the lake, usingGrauacke natural stone. The top parts of thestone layer are fixed in place by a TerraTreldouble wall that forms a safety rail.

A long lasting solution

The estimated life time of this solution is 70years. The sandy earthworks are reinforcedby the use of 50x4 mm2 galvanized steelsheet piles. The assembly is vandal proof,economic and long lasting, and pleasant tolook at.

Participants

Client: Fortis Vastgoed Ontwikkeling N.V., UtrechtArchitect: Kuin & Kuin Architectens - HertogenboschEngineer: Maasdonk’s Wegenbouw b.v., NulandSpecialised contractor and Supplier: Terre Armée b.v. – Breda

Real estate project


Netherlands

A new real estate project is now being built on the former Concordia deDen Bosch football field, in Holland. This luxury complex called “Vijverberg”involved the construction of 1 500 m2 of Reinforced Earth walls.

24 high security houses

THE OPERATOR OF THE KWAI CHUNG CONTAINER

terminal was quite satisfied with thecathodic protection installed by Freyssinet

nine years ago, and wanted a similar system toprotect the slabs of the wharfs in terminals.Corrosion of concrete reinforcement had causedspalling and other deterioration that allowed thepenetration of sodium chloride. Freyssinet HongKong was awarded the first phase of the work in

Kwai ChungTerminal 4

Protection of quays

August 2002, and installed a cathodic protectionon the underside of the concrete wharfs in theterminal, in cooperation with Corrosion ControlServices Limited, a subsidiary of FreyssinetLimited. The protection current is provided byflat anodes installed in slits formed on the con-crete surface and fully embedded in the repairmortar. Each part of the structure can be moni-tored, due to the breakdown into several anodic

areas. With this concept, it is possible to consid-er generalization of the system to all wharfs. Onthis site, Corrosion Control Services Limited isdoing the design, supply of specialised materialsand engineering supervision, while FreyssinetHong Kong is carrying out the supervision ofaccess works, concrete repair and installation ofcathodic protection systems. The completion ofthe work is planned for the end of July 2003.

Freyssinet magazine January/April 2003 - n° 216

Hong Kong

17

Portugal

SERPA BRIDGE ON THE E.N. 260 ROAD IN

south-eastern Portugal crosses theGuadiana river between Beja and Serpa.

This 400 m long prestressed concrete bridgewith a total width of 15.40 m was built in the1960s, and is composed of two variable depthbox girders. A recent inspection of the bridgefound severe deterioration of the structure; inparticular, technicians found cracks along thewebs of the box girders, advanced degradationof the bearings, large inclination of the con-crete pendulum bearing on the sliding bearingside, and deformation of the profile along thebridge. The Portuguese Government issued acall for bids during the year 2000 for renova-tion of the bridge. The contract was awarded

Computer aided renovation

Serpa bridge

Freyssinet-Terra Armada completed its first bridge strengthening projectusing replaceable external prestressing.

to Freyssinet-Terra Armada Portugal, whichhad proposed an alternative consisting of lift-ing the deck using the LAO (Computer AidedLifting) technique while changing the bear-ings, thus reducing the construction timetableby about two months. Therefore, the workdone by Freyssinet-Terra Armada Portugalincluded the construction design, and a gam-magraphy campaign to check the actual posi-tion of existing prestressing cables, to treatcracks, strengthen the structure by replaceableexternal prestressing tendons consisting of two24T15 cables for each box girder, and finally tostrengthen the abutments. Due to the computeraided lifting system, the bearings on piers werebrought back into the vertical position by

means of temporary sliding bearings, and theexpansion joints were replaced. Existing bear-ings on the concrete pendulum pier were alsoreplaced by a TETRON bearing sliding on themobile abutment.

Participants

Client: ICOR (Instituto para Construçao Rodoviaria)Design Office: Eng° Armando RITOMain contractor: Freyssinet-Terra Armada SAConstruction survey: Departemento Técnico de Madrid

Freyssinet Hong Kong is participating in the protection of slabs of wharfs in a container terminal.

A TERRIBLE EARTHQUAKE WITH AN AMPLITUDE

of more than 8 on the Richter scaleravaged part of Skopje in Macedonia,

on July 26, 1963. A project for reconstructionof the town was drawn up very shortly after-wards, but the plan was only progressively putinto application. One key element in this recon-struction was the construction of a bridge overthe Vardar river at the same location as the his-toric wooden bridge built in 1928 that hadbeen carried away by the 1962 flood. The newbridge was called the Goce Delcev bridge, afterthe man who created the first MacedonianRepublic at the beginning of the 20th century.The bridge construction work started in 1970.At the time, the central span was supported ona wooden falsework... that was carried away bya flood the next year! After this unfortunateepisode, the bridge span was increased andsteel falsework replaced the former wooden

Macedonia

18

structure. The two parallel decks are 136 mlong, with two 24 m long access spans and an88 m long and 17.8 m wide central span. Theconcrete box girder is transversely and longi-tudinally prestressed by 12ø7 cables.

Structural problems

This bridge quickly became a strategic trafficroute: it now carries 10 000 vehicles per day!But when it was put into service, shear forcecracks appeared adjacent to the piers. Thebridge gradually lost its camber, and the deflec-tion reached 450 mm in 2000. This degrada-tion was accompanied by severe infiltration ofrain water inside the box girder, because of thelack of waterproofing. Thus, a strengtheningplan was drawn up in 1994, started in 2001 and the constract was awarded to FreyssinetInternational and Cie.

A strengthening without traffic interruption

One of the first operations was to removeasphalt from the road and sidewalks surface,and the structure was then thoroughly cleaned.Damaged concrete areas of the deck sidewalkswere made up and all bridge fittings werereplaced, particularly including the placementof 72 m of expansion joints and 4 m of WOSdtype sidewalks joints. A waterproofing mem-brane was also installed, although there hadnot been one on the existing bridge, togetherwith gargoyles to evacuate rain water.Web cracks inside the box girder were grout-ed. Freyssinet then applied additional pre-stressing using four 19C15 cables, and theninstalled a deck anti-uplift system on the abut-ments using four 7C15 vertical cables. Theareas of maximum deflection were reinforcedby gluing carbon fiber fabrics (TFC) over anarea of 64 m2. All work was completed withoutany traffic interruption.

Participants

Financing: AFD (French Development Agency)Client: Town of SkopjeEngineer: Louis Berger and PX ConsultantMain contractor: Freyssinet International & Cie,in cooperation with Freyssinet BalkansDesign office: EEG Simecsol


The bridge over the Vardar river in the heart of Skopje has just beenrenovated after a very sad series of hazards. The story of a successfulrenovation operation.

A strategic routerescued from the water

Goce Delcev bridge


United States

An extension program is under way at the National City MarineTerminal in San Diego, California. The new complex underconstruction is located in an seismic area, and benefits from the know how of Ménard Soltraitement.

MÉNARD SOLTRAITEMENT WAS CALLED IN TO

participate in the work to prolong theSouthern end of quay 24-4, which is

part of the extension work on the National CityMarine Terminal in San Diego. This extensionwork includes widening of the shoreline bydriving sheet pile caissons and backfillingbehind the newly constructed curtain. It willbear a pontoon extending outside the line of thesheet piles. The new pontoon will be built ondriven piles and will be 340 m long by 25 mwide so that ships, each carrying more than4000 European vehicles, can be unloaded.

Seismic considerations

The work is done in the “San DiegoEmbayment”, which is a sedimentary basin lim-ited by a fault. Seismically, the site is located onthe area of the Rose Canyon fault, the mostactive main ramification of this area being theSilver Strand fault which is approximately 4 kmto the east. Seismic analyses carried out basedon initial geological records indicate that mostfill and deposits existing in the bay have a

Consolidation work

It was considered of utmost importance toimprove the characteristics of the materials usedfor filling the box girders and sloping materialunder the pontoon using the vibro-replacementmethod, to stabilize the system and ensure thatthe new pontoon would behave satisfactorily.This is a variant of vibro-compaction in whichballast is used to fill the hole bored by vibratingdrill. This method is used with low size gradematerials, since it reinforces the soil and drainswater overpressures through the stone columnsnetwork.The soil densification work currently being car-ried out is done after driving caissons and dredging the sloping material. They makeuse of the bottom feed system (ballast filledthrough the end of the vibrating probe) designed to operate under offshore conditions(slope densification). The installation of columnsis closely controlled during execution of thework using the Emparex System (record of con-struction parameters) and offshore columns arepositioned using a differential GPS.

“Vibro-replacement” forearthquake resistance

Extension to the National City Marine terminal

strong potential for liquefaction at depths of upto 18 m. The effects of soil liquefaction includeloss of foundation bearing capacity and sidefriction capacity, surface settlements and risksof circular slips in submarine slopes adjacent tothe sheet pile curtain.


“Incremental launching”as a solution

in extreme situations!Construction work on the West ring road for the town of Wroclaw has been going at full speed for several years.Designers recently needed to display all their ingenuity to build a crossing over three railway lines and a road carrying heavy traffic,using a viaduct.

Wroclaw viaduct

T HE FIRST RAILWAYS APPEARED IN WROCLAW

in 1842. Several stations and railway lineswere built to satisfy needs arising from

continuous development of the town in the19th century and then in the 20th century. Theseinfrastructures break the town into separateareas and create major obstacles to the smoothflow of road transport, which is why designersneeded to continuously think of more effec-tive means of constructing crossings. Theexample of the construction of the WroclawWest ring road viaduct is a good illustration.

Two construction methods

Wroclaw viaduct is more than 600 m long. Thetwelve tracks to be crossed (three railway lines)and the road are distributed over a width of400 m, which is why it was decided to build thecentral part of the viaduct by incrementallaunching, and to build its ends in situ. The pro-ject actually included two parallel structures; onefor the East road lanes and the other for the Westroad lanes. The project was built using pre-stressed concrete and used the Freyssinet C sys-tem. Associated work such as approaches werecast in situ. The West viaduct is 624 m long andthe East viaduct is 610 m long. The longest spanafter the temporary piles were removed is 52 m.The depth of the segments in the main viaductsis constant and equal to 2.5 m. A total of morethan 600tonnes of prestressing steel was used,

Poland

and construction of the decks took 14 months!The Freyssinet Group made an important con-tribution to this viaduct: Freyssinet Polska Sp.z.o.o. was responsible for launching and tension-ing on site, under the supervision of MaciejHildebrand. Freyssinet International and Cie'stechnical department designed and producedthe drawings of the precasting area, the nose andthe incremental launching equipment.

A total pushing force of7000kN

Different types of cables were used for construc-tion of the viaduct, including 19C15 main inter-nal cables, 19C15 external cables, 13C15 cablesfor incremental launching and sheathed greasedmonostrand transverse cables for the top slab.Each incrementally launched element is com-posed of 27 segments with an average length of15.5m and with a maximum length of 19m. Thespans were incrementally launched in successivelengths of 33.5 m and were equipped with a 26 mnose movement being controlled by a tensioningcomb and four RS230 jacks. The maximum totalforce during incremental launching was up toalmost 7000kN! A single operator performed alltensioning operations, using a single control deskfor wedging the SL230 jacks. These incrementallaunching operations are especially difficult, con-sidering the fact that most parts of the viaductsare curved in the horizontal and vertical planes.

Poland

Canada


No disturbance to traffic

The construction time for each segment wasone week. This work included two phases: thebottom slab and the two webs, and then thetop slab. The segment was assembled by pre-stressing with the previous element using sixor eight 13C15 cables, 24 hours after the topslab was cast. Transverse prestressing wasapplied at the same time. The assembly wasthus incrementally launched above the rail-ways and the road without disturbing rail orroad traffic. After the segments built by incre-mental launching had been put into the finalposition and the external parts had been madeon scaffolding, the keying joints were cast.Continuity cables were installed to achieve the

required load capacity and continuity of thebridge. Almost 370 tonnes of cables wereinstalled and tensioned during summer 2002,including lubricated external cables in HDPEsheaths. All cables were grouted using cementgrout except for the transverse monostrands.

Participants

Client: Wroclaw Roads and Public TransportAuthority Consultant: Mosty Wroclaw - Design and Test OfficeEngineer: Budimex Dromex S.A.Specialised contractor: Freyssinet Polska Sp. z.o.o.

Thanks to Reinforced Earth Canada's solution, the bridge providingaccess to the city of Perth East was replaced as a matter of urgency.

were created and the half-sections ofTechSpan arches placed on them using two165-tonne cranes. The building of the archtook eight hours and the front walls wereerected on both sides at the same time. Thenew Clemmer bridge is now made of a precastTechSpan arch and front walls made ofTerraClass facing. The arche has a clear span

of 18 metres, is 300 mm thick, 5.5 metres highand 10 metres long. In the words of Mr. GlennSchwendinger, Manager of Public Works for theTownship of Perth-East, “The use of this alterna-tive proved cost effective and extremely efficientwith respect to the time frame for the requiredroad closure. Thank you for RECO’s contributionto this success and the dedication of all your staff.”

Emergencyreconstruction

The Clemmer Bridge

THE TOWNSHIP OF PERTH EAST, IN THE

South-West of Ontario, needed to replacethe bridge crossing Smith Creek, a tribu-

tary of the river Nith. Inspections had discov-ered structural problems and, at the start ofthe 1980's, the authorities decided to reduce the traffic crossing the bridge. Thisdecision had serious consequences for thismajor road leading to the town and its 12,000 inhabitants. In 2001, the localauthority was warned that the bridge haddeteriorated further and that the public ser-vice vehicles used for snow clearing, roadmaintenance and fire fighting could no longercross it for safety reasons. It had to be closedor replaced. The first solution considered wasto build a new 18 metre long cast in situ struc-ture, estimated duration being three months.The second option, consisting of precastingsegments and assembling them on site, waschosen as the more economical solution. Theold structure was demolished and all thematerials recycled. Then foundation footings

After a barge collided with the central pier of Saint-SymphorienBridge in Ancelles, Freyssinet was asked to repair the structure. The drum beater did not slow down once during this operation.

January/April 2003 - n° 216

France

22

T HE SAINT-SYMPHORIEN CANTILEVER BRIDGE

was built between 1952 and 1953. It is atwin beam bridge with variable depth and

three spans including two almost 50m long endspans, and a central span composed of two27.3 m cantilevers supporting a 16.5 m singlespan. There is a 1 m wide sidewalk on each sideof the 6 m wide roadway. Transversely, thebridge comprises two concrete beams withvariable dimensions stiffened by triangulateddiaphragms.

The seriously damaged structure

On June 23 2001, a barge going downstream onthe Saône violently collided with the upstreambeam of the right bank end span… and serious-ly damaged the structure: the lower part of theupstream beam was destroyed at the support; theweb was broken and severely cracked over 7.5 m;the bottom of the downstream beam at the sup-port and diaphragms close to the deck spalledand cracked, like the deck at the two ends of theupstream beam.The structure was put into safe condition inDecember 2001 by means of a temporary bear-ing by lifting jacks with a capacity of 300 t. Agangway was installed in April 2002 so thatpedestrians would be able to cross while waitingfor the bridge to be repaired. Freyssinet wasappointed to do this work and the repair beganin mid-September 2002. In just three months,Freyssinet completely repaired all the damagecaused by the accident, and also made the bear-ings of the simple span and all facilities conform(handrails, expansion joints, etc.).

Three months renovation work

The objective for the upstream beam before therepair was to realign the bridge and redistributestresses in the area to be repaired. To achieve this,the bridge was firstly jacked using the lifting jacksplaced on the temporary bearing, placed underthe cantilever in the central span; secondly, crackslocated in the damaged area were filled. Afterdemolition of cracked areas and surface prepara-tion by high pressure water demolition, comple-mentary reinforcement was embedded in loadresisting areas in which the existing reinforce-ment was insufficient. The demolished area wasthen rebuilt in three phases; reconstruction of theconcrete at the beam bottom, concreting of theweb including conservation of a central keyingarea, controlled compression of the beam usingflat jack blocks and final keying of the whole sec-tion. Most of the work in the diaphragms con-sisted of filling the cracks. The upstream strut andthe horizontal tie rod of the most seriously dam-aged diaphragm were reconstructed. Before filling

the cracks, the downstream beam was entirelysand blasted and cleaned. The repair of the can-tilever span bearings included removal or demo-lition of expansion joints. The span was raised byalmost 1.5 m using a steel structure placed abovethe deck, to enable complete restoration of dam-aged areas at the ends of the beams. The fixedbearings of this span were removed and replacedby stainless steel bearings, mobile bearing strutswere sand blasted and metallized before the jackswere removed from the assembly. New roadexpansion joints were installed after the opera-tion was complete. The temporary structure andits supporting elements were removed at the endof the work.

Participants

Client: Saône-et-Loire departmentEngineer: CETE de LyonMain contractor: Freyssinet

Saint-Symphorien bridge

Express repair!

Freyssinet magazine

Tierra Armada, a subsidiary of Freyssinet in Spain, participated in construction of a motorway tunnel in the state of León.

Terre Armée SNC was asked to assist Valérian, the contractor, in the construction of eight road bridges.


Spain

23

France

T ierra Armada took part in the constructionof a cut and cover tunnel near Villafrancadel Bierzo, in the Spanish Peninsula in the

State of León. This structure, 2 x 170 m long, is11 m wide and 5.5 m high, and includes twoinclined openings. The central part of the right

road tunnel was cast in place using a ready-mixed concrete truck, while the left road tunnelwas cast in situ on a 0.15 m thick sacrificialformwork with exactly the same geometry as theprecast end arch. The 20 m end of each openingand the inclined openings were entirely precast.

Participants

Client: Ministry of the EconomyEngineer: Bierzo GroupSpecialised contractor: Tierra Armada S.A.

package was awarded to the Jean BernardEntreprise company. Both of these companiessubcontracted earthworks adjacent to thestructures to Valérian. This is the context inwhich Valérian has been building side and fac-ing walls made of rock-faced TerraTrel forthese eight bridges since July 2002 – obviouslywith the assistance of Terre Armée SNC.

Walls up to 8 m high

TerraTrel is a technology in which reinforce-ment is used in association with galvanized

welded mesh wall panels behind which thefill is completed by a 150 mm to 250 mmgranular material over an average width of 50 cm. Some of these walls, up to 8 m high, are vertical, while others are slightlyinclined. Terre Armée SNC's work started at the retaining wall design stage, and it has already provided Valérian with specificelements (surface panels, reinforcement andaccessories), and technical assistance. The last work package for two bridges is nowbeing awarded, and should be complete inspring 2003.

Concrete for acut and cover tunnel

TerraTrel walls with natural rock appearance

Motorway structure

Faulquemont deviation

T HE MOSELLE GENERAL COUNCIL APPOINT-ed the EEG Simecsol/APAAR Group tobe main contractor for work on the

Faulquemont deviation, as part of an improve-ment to the RD910 (Pont-à-Mousson to SaintAvold road). The design of bridges producedby the architect, François Doyelle, required useof rock faced TerraTrel type walls which is aReinforced Earth Group technology.After the call for bids issued in 2001, thesebridges were divided into three work pack-ages. The contractor, Demathieu & Bard, wasassigned two work packages and the third

reyssinet

France: Faulquemont bypassroad in Moselle. For thisproject, Terre Armée SNC is participating in the designof retaining walls, and thesupply of facings. It alsoprovides assistance forassembly.

Photo: Francis Vigouroux

January - April 2003

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