prestressed concrete floors

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PRESTRESSED CONCRETE FLOORSA Far-ReachingTechnique

THE FREYSSINET GROUP MAGAZINE&StructuresSoils

FOCUS LNG: CRYOGENIC PRESTRESSINGDERIVED FROM THE NUCLEAR INDUSTRY

REALIZATIONS KANNE BRIDGE (BELGIUM):A FIRST FOR COHESTRAND

HISTORY 1930-2005: THE RISE OF LIFTING

Know-how on the AgendaTurkey. On 31 May and 1 June last,under the respective chairmanship ofProfessor Erhan Karaesman and EmreAykar, Managing Director of Yapi Merkesi,Freyssinet International and Co. andFreysas, the Group’s Turkish subsidiary,organized two conferences in Ankaraand Istanbul on long span bridge designand associated construction methods.Around 200 people attended presentationsby Michel Virlogeux, Benoît Lecinq andJérôme Stubler at the conferences.

Prestressing Bars andCables on the TrackBelgium. The Belgian high speed rail network is beingextended and four new viaducts crossing severaldeep valleys on the line between Liège and theGerman border have just been completed.Between December 2004 and May 2005,Freyssinet Belgium contributed to theconstruction of these structures bysupplying and installing 650 pre-stressing bars to connectsupports and beams and1,200 t of cable (13C15,19C15) in the supports,beams and sub-bal-last slabs.

Natural Panels at the Zoo

Spain. The architects of the new Valencia Zoochose Reinforced Earth for the structures mark-ing the boundaries of the park’s different areas.Tierra Armada SA is currently building13,600 m2 of separating walls for the project.These will be clad with imitation stone panelsdecorated with themes inspired by the jungle.

P A N O R A M A

CONTENTSPANORAMAACTIVITY AND LIFE IN THE GROUPTHE WORLD IN BRIEF 2

CLOSE UPSUNGAI PRAI, READY FOR SERVICE 6

FOCUSLNG: CRYOGENIC PRESTRESSING DERIVEDFROM THE NUCLEAR INDUSTRY 8

REPORTPRESTRESSED CONCRETE FLOORS A Far-Reaching Technique 10

REALIZATIONSKANNE BRIDGE(BELGIUM) 16

MBABANE BY-PASS(SWAZILAND) 18

MONDRAGON PLATFORM(FRANCE) 19

MIRAGE TOWERS (MEXICO) 19

NUCLEAR CONTAINMENT VAULTS(INDIA, CHINA, FINLAND) 20

CALARASI PLATFORM(ROMANIA) 21

KWANG YANG PLATFORM (SOUTH KOREA) 22

THE LA SIOULE VIADUCT (FRANCE) 23

SAINT-CHÉRON RAIL BRIDGE (FRANCE) 24

KONIN BRIDGE (POLAND) 25

GAEGOK BRIDGE(SOUTH KOREA) 25

BAI CHAY BRIDGE(VIETNAM) 26

OUR PROFESSIONCMC OPERATOR: CONSTANT VIGILANCE 27

COMPANYA COMPREHENSIVE OFFERING IN SOUTH KOREA 28

HISTORYTHE RISE OF LIFTING 30

2 Soils & Structures Second half of 2005

PANORAMA

Supply and Support Morocco. Since February 2005, Freyssinethas been providing technical supporton the new Casablanca to El-Jadidamotorway to Moroccan company SGTM,which is building the bridge over theOum er-Rebia. Comprising two parallel500 m long decks made up of segmentscast in situ, this cantilevered structurewill carry four lanes of traffic. Freyssinetis supervising the construction workand has supplied two pairs of mobile rigsas well as the prestressing and worksequipment.

Third TechSpan ArchStructureUnited Arab Emirates. 150 km west of Doha on the Umm Bab-Salwa road, Reinforced Earth is working on the third site touse TechSpan prefabricated arches in Qatar. They are buildinga structure using 8 elements, each with an opening of 13 metresand a length of 34 metres. At each outlet the tunnel walls willbe given a Freyssisol facing.

ExternalPrestressingRussia. Since the beginningof June, Freyssinet has beensupplying and installingexternal prestressing for thesteel roof of a new ice rinkin Kolomna, near Moscow.The saddle roof is 250 m longand 150 m wide.

Successfor CMCsUnited-States. Withits proposal for a controlledmodulus column (CMC)soil treatment solution, DGI-Menard (Freyssinet)was awarded the contractfor works prior to theconstruction of a servicestation at Monongahelain Pennsylvania, whichit carried out during thesummer. Followingcompletion of the work,during which 135 CMCswere installed, thecompany won a newcontract of the same typein the Washington area.

United Arab Emirates. Freyssinet Gulf hasjust won the contract to supply and installthe prestressing (3,600 t) for the Ras AlKhor Bridge. Connecting the mainland part of Dubai to an11-kilometre long peninsula separated fromit by a sea inlet, the structure comprises twodecks providing six new traffic lanes andis made up of 8 spans, each with a lengthof 60 m.

3,600 tonnesof Prestressing

Landscape Integration

Spain. On the island of Tenerife inthe Canaries, two 5,580 m2 and 1,312 m2

tiered retaining walls, designed by TierraArmada (Freyssinet), were built during

widening works on the Tf-142 coastal roadbetween El Guincho and Icod. Particular

architectural care was taken over the facingpanels for the two structures in order to

ensure perfect integration into theenvironment.

Second half of 2005 Soils & Structures 3

Prestressing for Four Gas Storage TanksIran. With an area of over 1,300 km2, the South Pars fieldin the Persian Gulf is one of the world’s largest natural gasdeposits and its development means that ground installationsneed to be constructed regularly. Four storage tanks arecurrently being built, two with a volume of 55,000 m3

for propane storage and two with a volume of 45,000 m3 forbutane. Freyssinet has supplied and installed all of theprestressing for these four structures (900 t) and more than1,100 anchors.

Reinforced Earth on the Rome Ring RoadItaly. Having carried out the design work, Terra Armata issupplying the materials for several retaining walls for Rome’snew ring road.Measuring up to 14 m in height and 350 m in length, theseMSE structures use two types of facing, namely conventionalTerraClass cruciform concrete panels and TerraTrel welded mesh.

FIB Symposium 2005Hungary. Freyssinet and Pannon Freyssinet, the Group’sHungarian subsidiary, took part together in the FIB(federation internationale du béton - international federationfor structural concrete) symposium held between 23 and25 May in Budapest on the theme “Keep concrete attractive”.As well as presenting its most recent worldwide achievementswith special emphasis on those in Eastern Europe, theGroup also took part in the conference with a noteworthypresentation by Benoît Lecinq on the Kanne SuspensionBridge in Belgium and the use of the Cohestrand strand.

Mexico. The construction of a 365 m long bridge has just beencompleted near Texcapa on the Mexico City to Tuxpan motorway.The bridge deck is more than 100 m high at its highest point.Present at the site since December 2003, Freyssinet Mexicohandled the design and supply of the mobile rigs, expansion jointsand installed the prestressing.

High Link

50m-LongSpanSouth Korea. Equippedwith an MSS (movablescaffolding system) type self-launching truss,Freyssinet Korea is buildingboth parallel decks of the

Hwaebuk 1 (520 x 12.15 m) and Hwaebuk 2 (300 x 12.15 m)motorway bridges between the localities of Chungwon-gun andChungcheongbuk-do in the east of the country. The 60 m-longtruss, which weighs 200 t, allows for each 50 m-long prestressedspan to be completed in just 35 days.

P A N O R A M A


On the MoracaRiverMontenegro. After commencing inMay 2005, the installation of the staycables on the Millennium Bridge,near Podgorica, was completed atthe beginning of the summer and thestructure was inaugurated on 13 Julylast. Freyssinet supplied the staycables (300 t) for the structure, whichcrosses the Moraca River with a spanof 173 m and supervised theirinstallation by the general contractoras part of its role as technical supportprovider.

A Ready-to-Assemble Quay Cable-stayedroofingEgypt. To accommodatethe finals of the next AfricanFootball Cup of Nations,which will take place in Egyptin January and February 2006,Alexandria has started workon an 80,000 seat stadium.The suspension for theroof that will partly topthe structure consists of18 horizontal and 19 verticalstay cables supplied andinstalled by Freyssinet.

Mecatiss joins FreyssinetFrance. Following the integration of Salvarem at the beginning of 2005,the takeover of Mecatiss on 6 September 2005 strengthens the Group’scapabilities in the nuclear field. Headed by Bernard Marquez and attached to the Freyssinet StructuresDivision, Mecatiss designs, manufactures and implements fire barrier,leakage protection and radiation protection systems meeting the requirementsof the nuclear, petrochemical and shipbuilding industries and airports andpublic buildings. Equipped with an integrated test laboratory, the companypursues an active R&D programme and studies all new techniques andapplications relating to textiles, silicon elastomers, resins and mineral fibresto meet the specific needs of its customers.

Inspired FacingUnited States. Thetown of Castle Rock(Colorado) has justseen the completionof a road bridgecrossing a railwaytrack and a roadintersection.

Designed by the municipal authorities andconsulting engineers in consultation withthe inhabitants, the structure includes facinginspired by the rock pattern typical of theregion so that it blends into its environment.Reinforced Earth was given the job ofdesigning and supplying materials for theretaining walls. The company reproduced thepattern on the facing panels in six differentvariations. These were then arranged atrandom over the entire structure in order toreproduce the irregular appearance of therock as closely as possible.

750 t of Prestressingfor a ViaductHungary. In March 2006, Pannon Freyssinet,the Group’s Hungarian subsidiary, will beginthe installation of 750 t of internalprestressing for the Köröshegy viaduct.Located between Zamardi and Balatonszaszo,120 km south west of Budapest, this newstructure, which will carry the M7 motorway,is 1,800 m long and has 17 spans, the highestof which are 88 m at their highest points.

South Korea. The Pusan portauthorities have chosen a designfavouring protection for the installationof a new quay in an area of the portbattered by the swell. The structure(350 x 50 m) has been entrusted togeneral contractor Posco E&C Corp.,and makes heavy use of prefabricatedelements, which have beensubcontracted to Freyssinet Korea.To produce the structure’s 100 prestressedconcrete caissons, 800 slabs (8 x 4 m)and 500 vertical panels (22 x 1.6 m),the company will pour a total of15,000 m3 of high-performance concreteand install 729 t of prestressed steel.

PANORAMA


The Prai river has now been crossed: the last stay cables supporting the485 m long deck of the main bridge, at Butterworth in the west of the MalayPeninsula, were installed by Freyssinet on 25 July 2005. The company hasinstalled 112 stay cables to a demanding schedule on this structure since9 October 2004. The bridge is expected to open in January 2006.

Sungai Prai,Ready for Service

W I D E A N G L E


LNG: Cryogenic PrestressingDerived from the Nuclear Industry

Having played a role in equipping the containment vaultsof nuclear power stations all over the world for morethan 30 years, Freyssinet has worked tirelessly to perfectits prestressing system. Today, its quality andperformance make it the solution of excellence for theconstruction of liquefied natural gas (LNG) storage tanks.Jérôme Stubler, Deputy General Manager and StructureDivision Director, explains.

internal pressure thatcould be caused by anaccident, as well as fornormal operation forcertain storage tanks withinternal metal liners thatrest on the concrete shell.In both cases, the qualityof the prestressing is thedecisive element in thestructure’s performanceand durability. This quality,which has establishedFreyssinet in the field ofnuclear power stations,is also the mark of ourcapabilities in the LNGmarket. Over the last threeyears it has been illustratedon numerous storage tankconstruction sites all overthe world (see p. 9).

Costa Azul, a Project in Mexico with VINCI Construction Grands Projets

What makes Freyssinet’snuclear prestressingdifferent?Over the last 30 yearsthe company has beenassociated with theconstruction of all of thecontainment vaults forpower stations in Franceand a very large numberof those built inprestressed concrete allover the world. Today,the Company is presentin India and China atconventional powerstation sites as well as inFinland, where the firstEPR (European PressureReactor), due to take overfrom the plants currentlyin operation, is being built

Sols & Structures. - As apreferred player in thedevelopment of France’snuclear power stations,for which it suppliedand installed all theprestressing, Freyssinetis now positioning thistechnology on the marketfor liquefied natural gas(LNG) storage tanks.What exactly does thatinvolve?Jérôme Stubler. –Justlike the structure thathouses a nuclear reactor,the concrete shell ofa liquefied natural gasstorage tank is acontainment vessel. Theyare both circular vesselsdesigned to contain the

On 4 July 2005, as a subcontractor of VINCI Construc-tion Grands Projets, Freyssinet was awarded the con-tract for the supply and implementation of the pre-stressing for two liquid natural gas storage tanks inCosta Azul, south of Tijuana (Lower California), Mexico,a region with high levels of seismic activity. Thesestructures will be built by VINCI Construction MajorProjects for Sempra, an American gas sales company.

Each with a capacity of 160,000 m3, these two storagetanks will require the installation of 920 t of pre-stressing in the form of horizontal prestressing com-prising 19T15 cables and U-shaped vertical prestress-ing using 13T15 cables. The site was supplied with thefirst prestressing elements and materials in Septem-ber 2005 for implementation lasting from the end of2006 to spring 2007.

JÉRÔME STUBLER, DEPUTY GENERAL MANAGER

at Olkiluoto (see also p. 20). This success,originally linked toEDF’s requirements,which were decisivein the development ofhigh-performancemodels, is also a result ofinternal requirementsand has been illustratedover time by continuousprogress in the fields ofproducts, research andimplementation.Regarding productsspecially developed fornuclear power stations,one has to mention the55C15 anchor, the mostpowerful unit inexistence, the ductingsystems under ductile

rigid tubes, which providean additional guaranteeof the impermeabilityof structures, and specialthixotropic grouts(“Thixogel”) that allow fortotally bleed-free injection,thus giving optimal andlonger-lasting corrosionprotection. In parallel,new implementationprocedures have beendeveloped. These include equaltension jacks,which make it possibleto obtain the sametension in every strandand reduce creep, whichis another additionalguarantee of longevity.But Freyssinet’s nuclearprestressing service ismore than just a productsupply: the companydevelops detailedexecution methodsand provides site ownerswith dedicated teamshaving experience ofimplementation andthe very rigorousquality assuranceprocedures peculiar tostructures of this type.

F O C U S


So it’s a tried and testedmodel that Freyssinetis now using as a basisfor developing its positionin the LNG market?The similarity of thestructures and theimportance of the safetyand durability of thesestructures form the basisof the approach, whichaims above all to providethe appropriate technicalresponse, guaranteeingquality. LNG storagetanks have a specialfeature which is the verylow temperature, - 160°C,at which the gas mustbe kept in order for it toremain in a liquid state.As this temperature alsoaffects the structure,Freyssinet has workedon a "cryogenic"

prestressing, i.e. onethat retains its ductilityand does not becomeembrittled despite thetemperature conditions.The solutions proposedfor the two storage tankscurrently being built atChengdu in China havesuccessfully met thechallenge of cryogenicresistance tests. In parallel with this typeof technical response, andon the nuclear model,Freyssinet offers itscustomers anorganization that givesthem access to all of theexperience of Freyssinet’snetwork in both researchand operations.

So all in all, the offeringis customized to meet the

specialized requirementsof our customers?Faced with rising oil pricesand the prospect ofresources running out,gas, which also has thebenefit of a cleaner image,is becoming an attractiveenergy source and thenumber of developmentprojects is increasing. In2003, there were over100 exporting andreceiving terminals dueto be built worldwideby 2020, representingan investment ofapproximately 3 billioneuros. More recently, theChinese authorities haveannounced their desireto diversify their energysupply sources andincrease the proportionof natural gas to 7 or 8%.

In this very buoyantcontext, Freyssinet’sLNG prestressingservice thus has bothtechnical and economicadvantages. ■

In parallel, the last fewyears have seen a hugeincrease in the price ofsteel, making all-metalstorage tanks lesscompetitive.

FOCUS

Clients, sites, projectsIn 2004, Freyssinet supplied and installed 700 tof prestressing on the two 140,000 m3 storagetanks at Idku in Egypt, implemented withVINCI Construction Grands Projets.Eleven storage tanks are also under construction:•Sakhalin (Russia): Two 130,000 m3 storagetanks (750 t of prestressing);• Fos-Cavaou (France): Three 103,300 m3 storagetanks (1,400 t of prestressing);• South Pars (Iran): Two 55,000 m3 LPG (liquefiedpetroleum gas) storage tanks and two 40,000m3

LBG (liquefied butane gas) storage tanks (1,000 tof prestressing);•Chengdu (China): Two 160,000 m3 storage tanks(1,230 t of prestressing).Several others are being planned in Mexico (seebox) as well as UK, Spain, Belgium and Nigeria.

Idku (Egypt). Sakhalin (Russia).

South Pars (Iran). Altamira (Mexico).


MORE THAN HALF A CENTURYLATER the opposition encoun-

tered to prestressed floors inFrance is a reminder at Freyssinet ofthe opposition Eugène Freyssinethad to overcome at the time of hisinvention. Of course, this time it isnot a question of bringing aboutacceptance of an idea or a newmaterial, but of changing designand implementation habits inorder to allow the technique toextend its field of applicationbeyond the few cases where it isabsolutely necessary. "Luckilythere’s no shortage of references",

Market necessities, force of habitand the culture of the sectorhave favoured the growth of floorprestressing in many countries,but have not allowed it to developin France. This situation couldchange with the introduction ofnew regulations in 2006 and thanksto concerted efforts at Freyssinet.

comments Fernand De Melo,Freyssinet’s Technical Director inFrance who, having worked abroadfor a long time naturally mentionsAustralia, South East Asia, Singa-pore and Hong Kong, regionswhere the combination of rapidurban growth and a lack of spacehave favoured the technique."But," he emphasizes, "muchcloser to home, Great Britain is akey example, if not a model." (seepage 13). "On the one hand, theadvantages of the technique areglaringly obvious," continues theTechnical Director, inviting us tocompare two photos of car parks,one conventional, with a forest ofpillars, the other astonishingly spa-cious and clearly better able tofacilitate traffic movements andparking. "In fact," explains Fer-nand De Melo, "the advantage ofprestressing, which is found in civilengineering and the building tradewith this type of floor, can besummed up in two terms: increaseof span, which in this case can beup to 15 m as opposed to 7 to 8 m,and the weight reduction of struc-tures (floor thicknesses can bereduced from 40 to 20 or 25 cm)".This brings a whole range of advan-tages such as the reduction ofexpansion joints and the cost of

BONDED PRESTRESSING is made up of strands enclosed ina sheath injected with a rigid product (such as cement grout).

UN-BONDED PRESTRESSING is made up of sheathed greasedstrands directly installed within the floor slab or inserted intosheaths injected with a flexible product (wax, grease, etc.).

A FAR-REACHING TECHN

THE MALAYSIA TELECOMTOWER in Kuala Lumpur(Malaysia): 76 floors,230,000 m2 (1997).

R E P O R T P R E S T R E S S E D C O N C R E T E F L O O R S


A Full Range of SolutionsTWO TECHNIQUES...There are two types of technique for prestressed floors: pre-stressing by bonded post-tensioning, in which the bare strands ina smooth or ribbed sheath are injected with cement grout afterbeing tensioned and un-bonded prestressing, which uses strandsremaining free inside a sheath, where they are protected fromcorrosion by a grease.Un-bonded prestressing is often more economical for floors notsubjected to excessive loads. It is less advantageous if a highlevel of prestressing is needed (premises subjected to significantloads such as archive buildings) or if there is a risk that flooropenings will be made after pouring, since un-bonded prestress-ing requires the recreation of anchors after the tendons are cut.In certain cases, the two techniques are combined: bonded pre-stressing in beams and un-bonded prestressing in slabs.

…TWO SORTS OF STRAND, SEVERAL TYPES OF ANCHORThe two diameters of strand used are 15.70 mm (T15 strand)and 13 mm (T13). Depending on the diameter and the number ofstrands they receive (1, 3, 4, 5), the anchors are given codenames that are easy to decipher: 1E15 (1 strand of 15), 3E13,3E15, 4E13, 4E15, etc.

IMPLEMENTATIONSUnlike subcontract packages that do not interfere with the ’criti-cal path’ of the project, floor prestressing involves cooperationbetween the main structure contractor, who frequently carries outthe main work (formwork, passive reinforcement and concreteplacement), with the Freyssinet teams responsible for installing,inspecting and stressing the post-tensioning materials. Comply-ing with the positioning tolerances within the slab thickness iscritical to the execution phase. It has led Austress Freyssinet todevelop a range of "chairs" making it possible to guarantee thepositioning of the sheaths to a close tolerance. These are nowalso used in Great Britain.

can be gained every 20 to 25 floors.Finally, structural simplificationequals savings on materials and areduction in overall cost – advan-tages that companies can’t ignorewhen preparing their responses toinvitations to tender. Freyssinetestimates that savings of the orderof 15 to 20% can be made. Paradox-ically, since its appearance in the1980’s as an adaptation of the tech-nique used for civil engineeringstructures, floor prestressing hasnever really taken off in France.“Prestressing is not part of thebuilding construction culture in

France,” Fernand De Melo believes.“On the one hand, this is becauseconstruction design offices are notused to designing using the tech-nique, and on the other hand itsbecause general contractors thatcould turn to specialist designfirms are reluctant to do so for fearof losing control.” “It also suffersfrom a special technical status thatlimits it to such cases where thereare large spans, unusually heavylive loads and to what are known as’transfer floors’, where it representsthe necessary alternative to rein-forced concrete,” explains

maintaining them, etc. The bene-fits of the technique in terms ofapplications follow on very logi-cally from this basic data.

Vast Platforms

For architects and project man-agers, this makes it possible to“save space” with vast column freeplatforms, which are very

IQUE

favourable for creating openspaces that are easy to fit out andare highly suitable for office build-ings, as well as facilities such asshopping centres, airports and carparks. For building owners, thisspace saving also translates veryfirmly into extra square metres ofspace, particularly in the case ofvery tall buildings, where one level ▼ ▼

DOSSIER


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Christian Lacroix, FreyssinetRegional Director for Île-de-France. Regulations have also beena hindrance. The BPEL (béton pré-contraint aux états limites / pre-stressed concrete at limit states)calculation method used as a refer-ence by the technical inspectionservices is applicable to civil engi-

neering structures but has beenshown to be unfavourable for pre-stressed concrete floors, where itleads to an increase in passive steelquantities and consequently thecost price.In this apparently static context animportant change will neverthelessoccur as from 2006 with the intro-

duction of the Eurocode. Morefavourable to the technique, thisregulation drafted within the Euro-pean framework could restart aprocess by allowing companies touse the services of design firmsapplying the new calculationmethod, enabling them to maketheir designed structures more

innovative and competitive.“The Freyssinet technical depart-ment dedicated to prestressedfloors consists of a manager at eachof Freyssinet France’s regionaloffices and is responsible for ensur-ing that expertise is pooled andthat we function as a network,”says Fernand De Melo, “and we

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R E P O R T P R E S T R E S S E D C O N C R E T E F L O O R S


Great Britain: regulationschange everything

The Technique Saves Space andReduces the Overall Cost of Projects.

Over the last 20 years, the annual production volume ofprestressed floors in Britain is estimated to have increasedfrom less than 50,000 m2 to 1.3 million m2. At the endof a 2005 business year with a particularly large number ofprojects completed in Britain and Ireland, Patrick Nagle,Managing Director of British subsidiary Freyssinet Ltd.,and Paul Bottomley, Technical and Sales Director, answeredthree questions for Soils & Structures.

hope to be able to rely on Belgium,where Edouard Henrard has beenworking with a design firm for sometime.” Before the new regulationscome into force, this departmentwill also benefit from the calcula-tion expertise of two specialistengineers. In this field, supportfor the French team will comefrom across the Channel, wherethe British work according to aregulation (the British Standard)similar to the Eurocode and haveagreed to provide advice and sup-port in the selection and use of cal-culation software.

This success is the fruit of the long-term work undertaken by FreyssinetLtd. and other companies to changementalities and culture in the UnitedKingdom - and it took some time.Another explanation, linked to amore recent phenomenon, is thatthe increase in labour costs and steelprices has also increased the attrac-tion of prestressing. I would also addthe time saved on the site comparedwith a reinforced concrete solution,which accordingly represents afinancial saving for the general con-tractor and the space saving offeredby prestressed floors. In fact, withinthe same “shell”, the designer canplan for additional floors. Finally, Iwould say that the success has been

boosted by the increase in the aver-age height of buildings. In 2004 inManchester, Freyssinet Ltd made31,350 m2 of prestressed floors for a47-storey building, which is morethan 170 m high and will house theDeansgate Hilton Hotel.

Are British regulations favourableto this technique?PAUL BOTTOMLEY. – The obligationyou have in France to use a mini-mum amount of passive steel indefined locations does not exist tothe same extent in the UK. Here,the rules for the design of pre-stressed floors are defined byBritish Standard BS8110, supple-mented by technical report no. 43published by the Concrete Society.These recommendations are in factvery favourable to the technique,since they make it possible toreduce the conventional reinforce-ment to a minimum. In practice wecan often remove all the passivesteel in the bottom mat and most ofit in the top. This is completely

For bonded prestressing, thestrands are delivered to site onreels (weighing around 3 tonnes).They are unwound, cut to lengthand threaded into the sheathsbefore concreting (2). For un-bonded prestressing, thecables (1) are usually deliveredprefabricated (fitted with anchorsat the ends). They are installeddirectly in the reinforcements (3),on the chairs placed on the formwork.The cables can be tensioned using a light monostrand jack,generally three days after concreting, thus allowing for theremoval of the formwork (4-7).

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“Belgium: a 25-year lead, but the same obstacles”Over the last ten years, Freyssinet Belgium’s achieve-ments in Belgium and Luxembourg must representan average of 30,000 m2 of prestressed floors peryear," estimates Edouard Henrard, Sales Director ofFreyssinet Belgium. This figure simply reflects theadaptation of companies to their markets: in France,the development of the motorways generated a gooddeal of activity until 1985; this was not the case inBelgium, which is a small country where work of thistype was completed in 1970. Necessity knowing nolaw, it is now over 25 years since we turned to pre-

stressed floors and established contacts with veryactive design firms. Our first projects were officebuildings in Belgium and Luxembourg (offices for For-tis Banque, Brussels National Airport, the Social andEducational Institute and hospitals, car parks andshopping centres, open space offices, etc.). For allthat, we encountered the same obstacles as inFrance at all levels of the process. In France there isan additional handicap due to the considerable devel-opment of prefabrication and the market share ofthat technique in car parks and short-span buildings.”

How do you explain the success ofprestressed floors in Great Britain?Is it a recent phenomenon?PATRICK NAGLE. – 10 years ago we hadto canvass architects and consultingengineers, as it seems you have to doin France with your partners, inorder to convince them of theadvantages of floor prestressing.Those days are all but gone andsince the end of the 1990s, the trendhas changed and so have mentali-ties. Today, people approach us tocost solutions that incorporate pre-stressing right from the design stage.Cases come to us in the form of pre-liminary designs (slab configuration,thickness, loads) to be finalized,which is what our design office does.

DOSSIERDOSSIER


1. 72,000m2 of prestressed slabs were producedfor the Neder-over-Heembeek water treatment plantin Vilvoorde (Belgium).2. National Bank Tower in Abu Dhabi (United ArabEmirates).3. In the heart of London (United Kingdom), theprestigious Esso Glen office complex has a total of50,000m2 of prestressed floors.4. A car park without prestressed floors, with its forestof columns and cramped parking spaces.5. The car park at Atatürk airport in Istanbul (Turkey),designed with prestressed slabs, has large openspaces.6. Prestressing was used for the hemicycle at theEuropean Parliament in Strasbourg (1998) to reducethe height of the structure (thinner floors), providestability and earthquake-resistant monolithicbehaviour, and optimise the spans between shells.7. The prestressed slabs used for the new ExCelexhibition centre in London give the building a highload-bearing capacity.

“The Strength of Freyssinet Ltd. is its ConsiderableExpertise and its Design Office.”

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P R E S T R E S S E D C O N C R E T E F L O O R S

Emirates: a techniquethat meets a need

different from what is custom-ary and permitted in France. As wellas that, the strength of FreyssinetLtd. in this field is its considerableexpertise and its design office,which enable it to design and calcu-late prestressed floor solutions.

In practice, how is your work onsites organized, in particular withthe contractor in charge of themain structure?P. N. – Sometimes, particularly inIreland, we are involved with thegeneral contractor, but more oftenthan not our customer is in fact the”frame” contractor who is respon-sible for the formwork, reinforcingand placing the concrete. We workwith them to produce the slabs.Unlike in France, where small areasare worked on with daily rotations,we work on larger pour areas,sometimes greater than 1000 m2

with a cycle time of 4 to 6 days. Ourrole consists of installing the pre-stressing elements, tensioning thestrands and injecting the ductswith the cement grout. The tech-nique has not disrupted the organ-ization of sites as we are relativelyindependent in relation to theother operations. We are the oneswho adapt, and that’s why the mainstructure contractors use ourservices.

In the United Arab Emirates, floor prestressing hasbeen in regular use since the 1990s. Khalil Doghri,Managing Director of Freyssinet Middle East in Dubai,and Khalid Rabadi, Building Prestressing DivisionManager, explain why.

of the use of space and layout. Thisis exactly the type of span permit-ted by our technique, which alsobrings many other advantages,such as reduced floor thickness,elimination of beams, reduction inbuilding height, ease of installa-tion for air conditioning equip-ment, etc. The technique is alsoattractive for main structure con-tractors as it allows them to buildmore quickly using less steel andat a lower cost. As far as the spreadof the technique is concerned, weare in the opposite situation to theone in France, but for the samereason; force of habit, the cultureof engineers and the way compa-nies build have ensured the devel-opment of prestressing in thebuilding floors.

How is your cooperation with thegeneral contractors organized?KHALID RABADI. – Upstream of proj-

ects, our design office studies thesolutions to offer for the contrac-tors and quantifies the savings thatcan be made. These optimizedsolutions represent 50 to 60% ofthe contracts we handle. Once thecontractor is awarded the con-tract, we provide assistance withimplementation and materials,such as cables, sheaths, anchors,etc. Our site superintendentssupervise the general contractor’sworkers, who install the prestress-ing, but we are responsible for thework and are present at the time ofpouring. Beyond the technicalaspects we emphasize quality ofservice, which is an integral part oftechnical quality and the warrantygiven for the work. In practice, thisassumes faultless organization sothat the materials are suppliedexactly when they are required.We also have to coordinate ourinvolvement with the work on themain structure, which not all sup-pliers can do. We could doubtlessimprove our command of thisservice and our competitivenessby sharing our experiences moreat a Group level. ■

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What are the most important factsabout Freyssinet Middle East’sfloor prestressing business?KHALIL DOGHRI. – The technique,which is limited to bonded pre-stressing, began in the region inthe 1990s after being introducedby the Australians. Today it iswidely used in the Emirates, espe-cially in Dubai which is goingthrough a building boom – theworld’s tallest tower is being builtthere. Floor prestressing is part ofthe offering of many companies,some of which are from Asia, Aus-tralia, India, etc., including one ortwo general contractors that haveacquired the know-how forsmaller projects.

How do you explain this success?K. D. – Buildings with spans ofmore than 7 m are being suggestedincreasingly often by architects fortheir greater convenience in terms


OPENED TO SHIPPING IN 1939and 129 km long, the Albert

Canal, which connects Antwerp toLiège, today carries more than onethird of the traffic on Belgium’swaterway network. However, in theprovince of Limburg in Flanders, apart of the canal is still not accessi-ble to the 9,000 t pushed convoys,which have become the standardin Europe. Major enlargementworks have therefore been startedin order to modernize this strategicroute. Close to the city of Kanneto the south-west of Maastricht(Netherlands), the canal enlarge-ment has led to the replacement ofthe existing bowstring bridge by anew structure. "The suspensionbridge solution was chosen forarchitectural reasons and to pre-serve a high river gauge withouthaving to make access ramps thatwere too steep," says ClaudeMortier, Director of Freyssinet Bel-

STRUCTURES/KANNE BRIDGE

A First for Cohestrand Speciallydeveloped byFreyssinet tomeet theconstraints ofsuspension bridgeload-bearingcables, theCohestrandstrand has beenimplemented onan industrial scalefor the first timeon the KanneBridge in Belgium.

gium. This is the first structure ofthis type to be built in Belgiumsince the 1960s. The owner never-theless drew special attention tothe service life of the suspensioncables, which had to be compara-ble to that of stay cables, which inparticular meant guaranteeing thecontinuity of the anti-corrosionbarrier through the collars.”

Two 75-strand cables

Freyssinet’s Cohestrand system waschosen to meet this requirement(see opposite). “This site is also thefirst implementation on an indus-trial scale on a suspension bridge,"explains Benoît Lecinq, TechnicalDirector of Freyssinet. "Until now,only one prototype bridge with aspan of 88 m and main suspensioncables with 7 strands had been builtat Chartrouse in the Camargue on aprivate estate.” This new metalbridge comprises a main span96.20 m in length and two 14.80 m

Composition of theCohestrand strandMain element in tension. 7-wire strand with a nominal diameterof 15.7 mm, a breaking strength of 1,860 MPa and a fatigueresistance of 300 MPa over 2 million cycles.Protection against internal corrosion. Hot galvanization in accor-dance with standard NF A 35-035.External corrosion protection: high density polyethylene (blackHDPE, class PE 80 or PE 100) with a thickness of 1.5 mm,extruded on the strand and formulated to provide excellent agingresistance.Binder: consists of a polybutadiene resin surrounding all thewires, including the central wire, and an element to guaranteeadhesion to the polyethylene (this binding compound is ahydrophobic product, which is resistant to water vapour and oxy-gen and is capable of transferring the compression stress [flang-ing] and shear stress [tangential force of the hanger collar] fromthe polyethylene to the steel wires).

lateral spans. Mixed steel/concretestructure access viaducts flank thebridge. The deck, which is 21 mwide, carries two lanes of road traf-fic located between the hangerpositions and two tracks on the out-side for cycles and pedestrians only.

On either side, the load-bearingcables, each consisting of 75 strands,are supported by cylindrical masts25 m high (16 m above the deck).

A protective sheath

On each of the cables, 24 hangersspaced at 3.70 m bear the weight ofthe deck. Between the collars anexternal sheath in white HDPE spe-cially designed to protect thestrands against the effects of ultra-violet rays and mechanical stressescovers the load-bearing cable.“Each hanger consists of 5 x T15.7monostrands also housed in anexternal sheath in white HDPE,and can be likened to a Freyssinetstay cable,” adds Benoît Lecinq. Atthe level of the collar, the upperanchoring of the hanger is carriedout by an articulated clevis, whileat the lower level anchorage is on atube supporting the deck. Theinstallation of the suspension is thesite’s other special feature, as ittook place in the final phase of exe-cution. Prefabricated on the deckand supported by a temporary

R E A L I Z A T I O N S


apparatus, the cables, fitted withtheir collars, were put into place onthe pylons in two stages, using acrane for the first end, and by hoist-ing for the second. ■

Why choose Cohestrand?“The need for the main cables to be durablenaturally led to Cohestrand being chosen,”explains Benoît Lecinq, Freyssinet’s TechnicalDirector, “as this cable was specifically developedby Freyssinet at the end of the 1990s to resisttransverse flanging forces and longitudinal slidingforces and thus preserve the continuity of protec-tion against corrosion at the level of the hangercollars on suspension bridges or deviation saddleson cable-stayed bridges.Like the strands of a stay cable, with the petroleumwax replaced by a special resin in this case, theCohestrand strands have a triple protection barrier

– galvanization, interwire voids and voids betweenwire and sheath filled with an adhesive polymer,and HDPE sheath extruded and adhered to thestrand – the quality, homogeneity and reliability ofwhich are the fruit of industrial methods. And, likeparallel strand stay cables, the Cohestrand strandshave a potential service life of 100 years by design.A full scale test was also carried out on a section ofthe main cable to test the sliding resistance of thecollar. Conducted in August 2004 at the Freyssinetlaboratory, it proved that the collar was capable ofresisting a longitudinal force in excess of 1,200 kNbefore any sliding occurred.”

Owner: Ministerie van deVlaamse GemeenschapDepartement Leefmilieu enInfrastructuur Afdeling Maasen Albertkanaal.General Contractor: THVHerbosch Kiere AntwerpseBouwwerken - Louis Duchêne.Design Firm: IV-INFRA. Technical Inspection Service:Seco.Metal Construction: VictorBuyck Steel Construction.Specialist Contractor:Freyssinet Belgium andFreyssinet.

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On 5 December 2005, Antoine Zacharias,Chairman and CEO of VINCI, presentedthe grand prize in the VINCI InnovationAwards 2005 to Benoît Lecinq (technicaldirector of Freyssinet), Sébastien Petit (engi-neer within the "Cabled structures" division)and Ivica Zivanovic (product developmentmanager) for the "Cohestrand suspensionbridge cable system" used on the Kannebridge. In addition to technical innovation,the panel highlighted "the level of technolog-ical excellence achieved by the Freyssinetteams with this product."

VINCI Innovation Awards 2005: Grand Prize for Freyssinet

REALIZATIONS


MBABANE, THE CAPITAL OFSWAZILAND, a kingdom land-

locked between South Africa to thewest and Mozambique to the eastand barely 17,300 km2 in area, iscurrently served by two motorways,one from Manzini in the the southeast, and the other , from the bordertown of Ngwenya in the north west.Whilst the first of these goes all theway to the city limit, the second cur-rently ends about ten kilometresshort of Mbabane, where it joins an

SOILS/MBABANE BY-PASS

A Record Contract for 36,000 m2 of Reinforced Earth

In Swaziland, a relativelysmall Southern Africancountry, Reinforced Earth

has designed and is supplyingmaterials for several massive tieredfills, numerous bridge abutmentsand retaining walls for the capital’sby-pass link road.

old motorway (called the MR3 Cor-ridor), which is 5 km long and wasplanned to be modernized. In orderto create a link between these twoaxes without splitting the city intotwo, the country’s authorities haveopted for a by-pass solution, forwhich construction work began in2004. “We got involved with theMbabane by-pass and MR3 roadmodernization projects very earlyon, in September 2002,” saysAndrew Smith, Director of the

Southern African Reinforced Earthsubsidiary. The company’s techni-cal responses appear to have beenpersuasive and convincing. Twoyears later, Reinforced Earth signedone of its biggest contracts fordesigning and supplying 36,000 m2

of Reinforced Earth structures withWBHO, the general contractorresponsible for the construction.

789 km of reinforcing strips

The Reinforced Earth structures onthe Mbabane Bypass comprise14 retaining walls (totalling5,500 m2) 12 true abutments and4 mixed abutments for eightbridges (5,000 m2) and 4 tieredstructures – Mangwaneni (9,500 m2),Qabalembadada (8,500 m2), Esitebeni(4,500 m2) as well as a wall used asan access slip road at Mangwaneni(3,000 m2) – all to be constructedby 2007. “The tiered walls support-ing the line of the motorway werean alternative solution to the incre-

mentally- launched bridges origi-nally planned. These would havehad 30 to 40 m long spans on piersbetween 50 and 60 m high, saysAndrew Smith. The ReinforcedEarth tiered fills were proved to beeconomically, technically and envi-ronmentally acceptable solutionsfor containing the 35-metre highembankments. A 3m high 2m widetier pattern was adopted for thetiers except for the Esitebeni struc-ture which had to accommodate aservice road and the Qabalem-badada structure where the geom-etry dictated much higher tier wallsThe constituent materials for theReinforced Earth comprise weath-ered granite backfill TerraClass cru-ciform panels and HAR reinforcingstrips (Reinforced Earth highadherence steel strips) 45 mmwide, 5 mm thick, with lengthsvarying from 4 to 22 m. “All thematerials –a total of 1,735 t of steel,the equivalent of 789 km of rein-forcing strip – are planned to bedelivered before the end of 2005,”concludes Andrew Smith. ■

Owner: Swaziland Ministry ofPublic Works and Transport.Consulting Engineers:BCEOM/Otieno Odongo& Partners JV.General Contractor:WBHO South Africa.Specialist Sub-Contractor:Reinforced Earth (Pty) Ltd.

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SOILS/MONDRAGON PLATFORM

New Generation Ballasted Columns

a 5,700 m2 area of land at Mon-dragon (Vaucluse, France), wherea plant specializing in the transfor-mation of livestock slurry intocompost is due to be built. “It is acomplex process system thatrequired complete control ofabsolute and differential settle-ments, particularly in the 2,500 m2

area where a raft that will have tobear loads of 6 t/m2 is going to bebuilt,” says Ménard Soltraitementengineer Rémi Chatte. To treat thesoil, which is made up of silt andclay to a depth of 6 m, 980 bal-lasted columns (5,500 m) were putin place according to a squaremesh with side varying from 2 to2.50 m. With a record productionrate of 500 m per day (comparedwith 250 m with a conventional

MORE POWERFUL, FASTER,MORE EFFICIENT... the new

ballasted column machine jointlydeveloped by Ménard Soltraite-

The new high-performance Ménard Soltraitementcrane makes it possible to increase the size of ballastedcolumns. Demonstration at Mondragon.

machine), the work, carried out bya single shift of four people, lastedonly four weeks. The advantages ofthis new machine do not stopthere as they make it possible toestablish the ballasted columns ata depth of up to 16 m. It can alsodeliver a pressure of up to 35 twhen resting on its rear legs (25 tfor conventional models), thusimproving the quality of the bal-lasted columns (their peak resist-ance, tested using a static pen-etrometer, varies between 20 and30 MPa). “We even set a record val-idated by a bailiff at the previoustest site, recording a pressure of38 t”, adds Rémi Chatte. ■

Owner: Société de distributiond’eau intercommunale.Project Manager: Safegeenvironnement.General Contractor:groupement Spie-BatignollesSud-Est - Mathis -Screg Sud-Est.Specialist Contractor: Ménard Soltraitement.

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STRUCTURES/MIRAGE TOWERS

57,300 m2 of prestressedfloors in Mexico

IN THE HEART OF LA LOMA, a residential district of the Santa Fe quarter inMexico City, a complex with a total of 235 apartments has recently been

built over an area of 15,000 m2. In order to optimize the habitable area andlighten the structure of the Mirage Towers, three 17-storey buildings con-structed above three underground carpark levels, architect José Luis CambaCastañeda opted for the prestressedconcrete slab solution. A total of57,300 m2 of prestressed floor surfacewas produced, using 160 t of extrudedmonostrands supplied and installedby Freyssinet de Mexico. ■

ment and Enteco under the codename E600 has many advantages.It has just been used for the sec-ond time in the field to consolidate

Owner: Celta Bienes Raices,SA de CV.Project Manager: José LuisCamba Castañeda.Specialist Contractor:Freyssinet de Mexico.

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REALIZATIONS


STRUCTURES/NUCLEAR CONTAINMENT VAULTS

World-renowned expertiseAs a prestressing specialist fornuclear power station containmentvaults, Freyssinet has handled theinstallation of over one hundredprojects in 13 countries over morethan 30 years.

1. Construction of the foundations of the containment vault forthe new EPR European reactor in Olkiluoto. 2. Anchor point forthe vertical prestressing for a containment vault in China.1

IN THE STATE OF TAMIL NADU,in southern India, two VVER 1000

type reactors of Russian design arecurrently being installed near thetown of Trivandrum on theKudankulam site. For each of thetwo containment vaults, compris-ing a prestressed concrete shell1,200 mm thick reinforced with a6 mm metal interior impermeabil-ity liner, Freyssinet has installed60 vertical inverted U-shaped pre-stressing cables, 53 horizontalcables looped on two ribs and15 horizontal cables looped on thedome, all made up of 55-strandsheathed and greased bundlesinjected with cement grout beforetensioning. “2,713 t of steel and

514 type 55 C 15 anchors havebeen installed,” says Jean-LucienMongauze, Business Engineer atFreyssinet. The strands arethreaded one at time into a flexiblesheath in the case of horizontalcables, and into rigid tubes for ver-tical prestressing. As un-bondedprestressing is used, load-check,re-tensioning or replacementoperations can be carried out laterif necessary.In China, Freyssinet has just fin-ished installing the prestressing fortwo containment vaults at theTian-wan power station near thecity of Lianyungang in Jiangsuprovince. Freyssinet is also provid-ing assistance for the construction

anchors and 580 37 K 16 anchorags.The second project, Qinshan phaseII, relates to the enlargement of theQinshan II power station, whichwas built between 1996 and 2002.Less powerful than Ling-Ao with apower production capacity of 600MW, this power station was largelydesigned by Chinese engineers. Forthe containment vaults, 174 19 T 6dome cables, 199 19 T 16 horizontalcables and 144 37 T 16 verticalcables were put in place by the gen-eral contractor with the technicalassistance of Freyssinet.In Europe, Freyssinet is working inFinland on the new EPR (EuropeanPressure Reactor) constructionproject on the Olkiluoto site. This is

of two nuclear power stationsnamed Ling-Ao phase II and Qin-shan Extension phase II by supply-ing and installing the prestressingfor the containment vaults (37 m indiameter and 56.70 m high). Thefirst is an extension of the Ling-Aophase I power station (itself anextension of the Daya Bay powerstation), constructed in theprovince of Guandong south ofShenzhen between 1997 and 2002and equipped with two 900 MWPWR reactors. The prestressing sys-tem used is made up of 176 19 T 16dome cables, 224 horizontal cablesof the same type and 145 37 T 16vertical cables. This amounts to2,506 t of strands, 1,600 19 K 16

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an exceptional programme which,for the protection of the reactor,requires a non-standard doubleshell comprising a 1,800 mm thickshell to protect against planecrashes covering the entire nuclearisland and an internal vault1,300 mm thick, with a 6 mm-thickmetal liner on the inside to guaran-tee impermeability. Acting onbehalf of Framatome, Freyssinet is supplying a turnkey service forthe provision and the installationof prestressing for the internal containment vault. Thus 104 54 T 16gamma cables, 119 54 T 16 hori-zontal cables and 47 54 T 16 verticalcables have been installed, with a total of 2,050 t of strands and 540 55 C 15 anchors.

Installation and inspection

“The containment vault is the ulti-mate barrier in the event of anaccident,” points out Jean-LucienMongauze. This means that itsconstruction and the installationof prestressing are matters for spe-cialists that must comply withstringent quality requirements andthat require very strong cables.Since its first involvement in theFrench nuclear programme withEDF during the 1970s, Freyssinethas continued to improve its pre-stressing system. In particular ithas developed new injected groutsand improved the impermeability

SOILS/CALARASI PLATFORM

Record Output

DURING THE SUMMER, MénardSoltraitement put a great deal of

effort into successfully completingthe improvement of a 21,500 m2

platform in Romania. For the con-struction of its new flat glass man-ufacturing plant, a project involv-ing in particular a 21,500m2 storagewarehouse that will have to bear alive load due to use and occupancyof 8 t/m2, Saint-Gobain chose thetown of Calarasi, approximately100 kilometres east of Bucharest, asite where the soil conditions(compressible collapsible loess andsoft clay) and the seismic risk madestrengthening necessary. TheMénard Soltraitement solution wasfinally chosen in preference to theinitial plan for a floor supported onpiles. It consisted in installing con-ventional paving with a thicknessof 25 cm resting on soil strength-ened by a network of CMCs (con-trolled modulus columns) via asand-gravel mixture distributioncushion with a thickness of 60 cm.“With this solution we were able toguarantee absolute settlement ofaround 3 cm and differential settle-ment of less than 1/500°,” saysPhilippe Liausu, Managing Directorof Ménard Soltraitement. In orderto carry out the work within the very

tight deadlines without risking pro-hibitive penalties for delay, in Julyand August last, the companyenlisted two CMC rigs and installed3,900 CMCs with a 360 mm diame-ter (equivalent to 65,000 linearmetres) according to a 2.25 msquare mesh at a mean depth of17 m. The sustained rate allowed usto achieve a production record of1,740 linear metres of columns for aone workshop working one 12-hourshift, equivalent to approximately200 m3 of mortar. “We also had touse three concreting plants so thatwe could produce the 8,000 m3 ofmortar we needed,” adds PhilippeLiausu. The mobilization paid off:the company delivered the workthree days ahead of schedule. ■

Owner: Saint-Gobain.General Contractor: Hervé. Technical Inspection Service:Socotec.Specialist Contractor:Ménard Soltraitement.

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and rigidity of ducts by using rigidtubes for the vertical parts or partswith large curves, as well as ther-moshrinkable sleeves and injec-tion connections.Freyssinet’s current offering com-prises several types of prestressingchosen to take account of the tech-nical specifications, the mainte-nance, the replacement and the lifetime of nuclear plants.In addition to these installationservices, Freyssinet offers its cus-tomers inspection and monitoringof the prestressing during andafter the works. “We have variousmeasurement systems available tous,” says Jean-Lucien Mongauze.In some cases, as well as exten-someters with vibrating cords thatgive information regarding the sta-tus of the stresses within the con-crete, we also equip a few cables of each type with dynamometers.In the other cases, we also have the possibility of load-checking allthe cables using the lift-offmethod and checking for the pres-ence of any corrosion by de-ten-sioning and examining some of the strands during power sta-tion maintenance shutdowns.Freyssinet will also design andsupply gondolas and service tow-ers to provide access to the cablesand to install and inspect themduring the lifetime of the powerstation. ■

In July and August, the twoCMC rigs enlisted consolidatedthe platform that will holdthe new Saint-Gobain plantin Romania.

256 prestressing cables were installed in the two containmentvaults in Kudankulam (India).

REALIZATIONS


SOILS/KWANG YANG PLATFORM

AtmosphericConsolidationover 350,000 m2

At Kwang Yang (SouthKorea), the Menard Vacuumprocess makes possible

to consolidate land claimed fromthe sea.

+ 8.50. There is therefore a total of25 m of very soft, waterlogged clay,onto which a geotextile is unrolled.This is then covered with a sandydraining cushionand a layer ofungraded aggregate.

A Network of Drains

“This is the point where SangjeeMenard comes into action to installcylindrical vertical drains in thesoil in a 1-metre square mesh,”explains Daniel Berthier. From June 2005, 55,000 drains(1,300,000 lm) sunk to a depth of26 m underground were installed injust under one and a half monthswith to the mobilization of twoinstallation teams turning out12,000 m per machine per day. Sub-jected to the pressure of the backfill

(and, later, to the pressure drop cre-ated by pumping), the watertrapped in the clay flows up towardthe upper layer of sand where it iscollected by a system of horizontaldrains, which are connected topumps. In order to increase theimperviousness of the system andin particular to counteract theharmful effect of sand lenses in thedredged clay, a slurry wall made ofsecant piles was constructed on theentire circumference by mixing thein situ soil with a bentonite/cementgrout. In addition, interconnectedsteel sheets were put onto theupper part of the slurry wall inorder to improve its effectiveness.An HDPE membrane with a thick-ness of 1.50 mm, sealed into theclay in the trenches dug out abovethe slurry wall and covering all ofthe backfill, completes the installa-tion. Then, after meticulous check-ing of the system for leaks, pump-ing was activated. As the pumpscreate a vacuum under the mem-brane and remove the water fromthe soil, the ground is restructuredby settlement. This undergroundwork is supplemented at the sur-face by the excess load effect ofbackfill placed above the mem-brane. On the lot on which workhas just started, a global settlementof 7 m is expected in a 12 monthsperiod, with residual settlementguaranteed for 10 years, of 10 cm inprimary consolidation under anoperating load of 5 t/m2. ■SOUTH KOREAN AUTHORITIES

have decided to make the portof Kwang Yang, located in thesouth of the country near Yosu,one of the most dynamic portareas in Asia. This implies anincrease in container storagecapacity and the number ofunloading docks at the site. Titanicsea filling works have thereforebeen underway at the port for sev-eral years. The operation consistsof filling immense racks formed bydykes of rocky ballast withdredged clay on the soft marineclay sea bed; the quay edge ismade up of concrete caissons sub-merged in the sea. As the resist-

ance of land obtained in this way isvery poor, consolidation was nec-essary. “The treatment by atmos-pheric consolidation (Menard Vac-uum process) we suggested waschosen in 2003 for treating an ini-tial platform of 295,000 m2 (lot 3-1)which has just been delivered,”says Daniel Berthier, vice chair-man of Sangjee Menard. “Thecompany has just begun work on asecond area of 55,000 m2 (lot 3-2).”The implementation of theprocess involves several stages. Inthe case of lot 3-2, the clayey sub-marine deposits are approximately15 m thick and are topped by thehydraulic dredging backfill to

The underground network of 1,300 km of drains connected topumps will allow for the soil to be restructured within 12 months.



STRUCTURES/THE LA SIOULE VIADUCT

1,200 t of Multiple PrestressingStrands

In the Puy-de-Dôme, workhas just been completed onthe largest concrete viaduct

in France, a structure in whichprestressing is present throughout.

cables according to the piers). Onthe upper part of the segments, inthe upper block, monostrands werethen installed transversally every250 mm. “We suggested usingsheathed and greased strands as analternative to a solution that wouldhave required larger units andwould therefore have been moredifficult to install,” explains AlainGhenassia. During the constructionof the spans, initial interior pre-stressing was installed to tie the seg-ments together and take the inher-ent weight of the structure.Anchored per pair of segments oneither side of the piers, these cablesare formed of bundles of 19 bare15.70 mm strands inserted into ametal sheath injected with cementgrout, the longest of which is 200 min length.Finally, external continuity pre-stressing by cables (31C15) measur-ing up to 250 m was installed in thecaisson between December 2004and July 2005 to carry the structure’soperational loads. Inserted into a

Owner: Autoroutes du Sud de la France.Project Manager: Setec TPI.Designer: Secoa.Architect: Berdj Mikaelian.General Contractor: Campenon Bernard TP-Dodin JV.Specialist Contractor:Freyssinet.

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IN THE AUVERGNE VOLCANOESNATIONAL PARK, between the

villages of Bromont-Lamothe andSaint-Ours-les-Roches, construc-tion of the la Sioule viaduct on theA89 (Clermont-Ferrand – Bor-deaux) was completed last Sep-tember. Designed by the Sociétéd’études et de calculs en ouvragesd’art (Secoa) and architect BerdjMikaelian, the structure comprisesa single concrete box-girder, theheight of which varies from 5.50 mat the midspan stitch to 10 m atthe the piers. Its eight spans, thetwo central ones stretching 192 meach, rest on hollow reinforcedconcrete piers, the highest ofwhich rises to 135 m.

1,200 Tonnes of Steel

For the deck, the CampenonBernard-Dodin group of compa-nies (VINCI Construction) chosethe balanced cantilever construc-tion method with segments cast insitu and entrusted the prestressingto Freyssinet. “It would be moreaccurate to say the “prestressings,”says Alain Ghenassia, Freyssinet’sRhône-Alpes regional director.“They all use our C system and rep-resent a total of 1,200 t of steel."Chronologically, a transversal pre-stressing injected with cementgrout was first applied to the lowerhollow block of the segments onpiers (themselves “tacked” to thepier heads using two or four 19T15

black HDPE sheath injected withpetroleum wax in accordance withCIP (Commission inter-ministériellede la précontrainte/interministerialprestressing commission) recom-mendations, these can be re-ten-sioned or even individually replacedif necessary.After 36 months of civil engineer-ing works, the viaduct will open totraffic at the beginning of 2006. ■

The deck houses two setsof prestressing: one tyingthe segments together oneither side of the piers, theother bearing the structure’soperational loads.

REALIZATIONS




As it only requires smallteams to work on thelower part of the structure,the technique is alsobeneficial in terms of riskprevention.

STRUCTURES/SAINT-CHÉRON RAIL BRIDGE

Express Method fora Railway Bridge

Acquired byFreyssinet atthe beginningof the year, theAutoripage®

technique makesit possible toput a structurein place on arailway line withrail trafficinterrupted foronly a few hours.Illustration inSaint-Chéron(France).

IN THE TOWN OF SAINT-CHÉRON (ESSONNE), the level

crossing on the Brétigny-Toursline is now just a memory formotorists. They can now cross therailway line with the greatest ofease thanks to the restructuring ofthe RD 116 road and the construc-tion of a rail bridge, which wasinstalled within a few hours thanksto Autoripage®, a technique thatwas added to the Freyssinet con-struction offering with the acquisi-tion of the company JMB Méthodeslast January.

50 metres in 5 hours

“We allowed a window of 12 hoursfor safety, but in the end we onlyneeded 5 hours to carry out themanoeuvre and slide the structurefrom its prefabrication area to itsfinal location,” says Jean-Luc

Bringer, Director of the SCCM(Service centralisé câbles et manu-tention/Centralized Cables andHandling Service) unit atFreyssinet. This time saving of sev-eral hours was in fact part of amuch greater time saving if youconsider the project as a whole.“The conventional solution wouldhave been to build a bridgedirectly on the route and move railtraffic onto a temporary structure,which would have led to a signifi-cant reduction in average trainspeed, or sometimes trains evenhaving to be stopped,” explainsJean-Marie Beauthier, inventor of

the process. With Autoripage®, thebridge is entirely prefabricated inan area adjacent to the railwayembankment before being put inplace. Apart from for the very lim-ited time needed for this opera-tion, which means stopping trafficfor between 10 and 48 hours, traintraffic is not disrupted at all whilethe structure is being built.Placed on its raft 50 m away fromits final location, the Saint-Chéronrail bridge was a 2,400 t structurewith a length of 35 m and a skew of74 degrees with two central spans,one for road traffic (12 metreswide), the other for cyclists (4mwide), flanked by two approachspans. The bridge was put in placeby sliding using a system of cablesand three jacks used as linearwinches with a unit capacity of1,000 t and a stroke of 350 mm,specially designed for this type ofactivity by Hebetec, the Freyssinetsubsidiary specializing in heavyload handling. “Using this systemwe can reach a maximum pushingspeed of 12 to 13 metres per hour,”says Martin Duroyon, SectionEngineer at Freyssinet. At Saint-Chéron, this pace was reduced byhalf to allow the excavators to clearthe embankment ahead. This teamoperation also received a contri-bution from Advitam, a companyassociated with the VINCI Group,which developed a monitoringsystem to ensure centralized con-trol of the jacks and monitoring ofthe structure’s movement (meas-urement of displacements andloads, altimetric and lateral move-ments).

Autoripage®: the principle

Invented by Jean-Marie Beauthierin 1992, the Autoripage® technique

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REALIZATIONS


Railway Works Owner: RFF.Road Works Owner: ConseilGénéral de l’EssonneAssistant Project Manager:SNCF Rive GaucheProject Manager: SNCF-EVENVal d’orgeGeneral Contractor: GuintoliAutoripage: Freyssinet France,Service centralisé câbles etmanutention (SCCM)Design and Methods: JMBMéthodes

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PARTICIPANTS

consists of moving an entire struc-ture such as a rail bridge from itsprefabrication area to its finallocation within a very short time,thus limiting interruptions to railtraffic to between 10 and 48 hours.The structures to which it isapplied are assembled on a raftand comprise two approach spanssupported by struts inclined at 45°,which replace the traditionalripraps (this configuration makesit possible to avoid filling opera-tions around the structure at alater stage and the construction ofa transition slab or wing walls).The actual Autoripage® operationinvolves sliding the structure to itsfinal location on the soil on a bedof lubricating bentonite-basedgrout using a system of cables andhydraulic jacks. As the structureonly exerts very low pressure onthe soil (0.3 to 0.7 bar), Autoripage®

can be used on any type of ground.Since the takeover of JMB Mé-thodes by Freyssinet, several struc-tures have been constructed usingthis technique in Thonon-les-Bains, Thaon-les-Vosges, Saint-Rémy-lès-Chevreuse, Chalon-sur-Saône, in Luxembourg, etc. ■

STRUCTURES/KONIN BRIDGE

Incremental launching on the River WartaIN KONIN (POLAND), on the

Warsaw to Poznan motorway,Freyssinet Polska, the Group’s Pol-ish subsidiary, has assisted withthe construction of a new steelbridge by handling the incremen-tal launching operations above theRiver Warta. Generally curved inshape, the structure measures440 m and comprises five rectilin-ear spans. The deck was put inplace in 220 m (780 t) sections intwo phases, in July and August, inonly five days. “The main difficultywe encountered,” explains AnnaOldziejewska, Marketing Managerat Freyssinet Polska, “was in thearc-shaped geometry of the struc-ture, and its lower wings, neitherthe width nor the height of whichwere constant.” To compensate for

these differences and to allow thestructure to rest axially on thesupports, mobile ’auto-centred’devices (specially designed byFreyssinet for this structure) com-bined with five jacks with a unitcapacity of 30 t were used.

The actual incremental launchingrequired the use of four jacks witha stroke of 60 mm using a force of892 kN. Once the incrementallaunching operations were fin-ished, Freyssinet Polska installed60 pot bearings. ■

STRUCTURES/GAEGOK BRIDGE

A 100% Freyssinet Project

In South Korea a new motorwaysection passes through a particu-

larly hilly area close to Geagok andcrosses a structure that is 280 mlong (and 20 m wide), whichFreyssinet Korea will be building in

its entirety, including the civil engi-neering.Resting on piers of up to 50 m inheight, the deck comprises fivecantilevered spans (70, 50, 55, 35and 70 m) and has interior pre-

stressing made up of un-bonded19C13 cables (220 t). “Our team onsite, made up of 35 people, buildone segment on each side of thepiers every 18 days,” says Jong TaeHan, Works Director at FreyssinetKorea. The abutments are built onscaffolding. When the structure iscompleted in June 2006, theFreyssinet Korea teams will remainin the region and will begin workon another structure on the sameroute, the Beobgy I Bridge, with a20 m wide, 180 m long deck. ■

Owner: Gyeongsangnam-do.General Contractor: DaewooE&C Corporation.Specialist Contractor:Freyssinet Korea.

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PARTICIPANTS



Owner: Socialist Republic ofVietnam – Transport Ministry –Project no. 18.Finance: Japan Bank forInternational Cooperation.Project Manager: Japan Bridge& Structure Institute Inc. ;Pacific ConsultantsInternational; TransportEngineering DesignIncorporation; Hyder Consulting-CDC Ltd.Specialist Contractor:Freyssinet.

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PARTICIPANTS

LOCATED ON THE ROUTE OFTHE FUTURE MOTORWAY

No. 18, which will connect Noi BaiInternational Airport to the north

STRUCTURES/BAI CHAY BRIDGE

LandscapedStay Cables onHalong Bay

In the Gulf of Tonkin(Vietnam) on the edgeof Halong Bay, construction

of the Bai Chay Bridge is in progress.The structure is fitted with the latestgeneration of Freyssinet stay cablesand pipes.

of Hanoi to Bac Luan on the Chi-nese border, in 2006 the Bai ChayBridge will cross a sea inlet over-looking Halong Bay and will be the

key to the economic developmentof a high-potential region, which isstimulated by both the location ofthe industrial city of Haiphongalongside the motorway and theBay’s significant tourist and portactivity.With a central span of 435 m and atotal length of 903 m, the Bai Chaybridge is larger than the Elorn(France), Sunshine Skyway (UnitedStates) or Coatzacoalcos (Mexico)bridges and breaks the lengthrecord for prestressed concretebridges supported by a centrallayer of stay cables. “The arrange-ment of the stay cables does notreflect a desire to break a record,”explains Roger Raymond, FreyssinetArea Manager, “but rather an effortto enhance a UNESCO world her-itage site.” With two lanes of trafficin each direction as well as twofootpaths, the deck, comprisingsegments cast in situ, is 25.30 mwide. The cantilevered structurewill be supported by 112 stay cablesanchored into two pylons reachinga height of more than 137 m.

A Special Pipe

Depending on their location, thebundles of cables are made up of37 to 75 strands and their lengthvaries from 50 to 230 m. All of themare fed into a ’low drag stay pipe’,which is fitted with a specificdevice to prevent vibrations linkedto the combined action of the windand rain. The originality of the BaiChay pipes goes further, as theowner wanted to use three shadesof yellow on them to create shadedtones in trompe l’oeil reminiscentof a sunset from the centre of thepylons outwards. “Thanks to itsmastery of stay cable technology,Freyssinet was able to respondfavourably to this request,” saysBenoît Lecinq, Freyssinet’s Techni-cal Director. “Our R&D work hasenabled us to find formulations forthe sheaths to allow the designersto give their architectural expres-sion free rein. Freyssinet offers itscustomers pipes in various coloursthat preserve their mechanicalproperties and their resistance toultraviolet rays.” To absorb vibra-tions, the bridge will also beequipped with three types of inter-nal damper depending on thelength of the stay cables. 20 inter-nal radial dampers (IRD) per pylonwill be installed on the longestcables, 20 internal hydraulicdampers (IHD) for intermediatelengths and 16 internal elastomericdampers (HDR) for the shortestones. ■

A central layer of stay cables,narrower protective pipesin special colours: threesolutions to help the structureblend into the panorama.


O U R P R O F E S S I O N

«When we arrive at a site,”explains Mathieu Prot, a

Controlled Modulus ColumnOperator (see below) for MénardSoltraitement, “the first thing wedo is check the equipment in itsentirety – that is, the crane, itsmast and the concrete pump sup-plying it – and make sure every-thing is working properly. InstallingCMCs leaves no room for improvi-sation and the type of concrete weuse means we have to work non-stop.” As soon as he has finished hischeck-up, the operator goes to hisworkstation, a cabin with controllevers arranged next to a computerscreen. He will only come out againonce the concrete supply to thepump has been used up (45 or 90 m3

depending on the model).On the ground, marking set out bythe Ménard Soltraitement engi-neers shows him the exact positionof the CMCs to be installed. Guidedby a manoeuvre that controls themovement of both the pump and atracked remote-controlled device,the operator places the auger accu-rately on the marks, ensuring thatthe mast is vertical and if necessaryadjusting it using an inclinometer.As soon the auger starts to pene-trate the soil, all the drilling param-

eters are recorded by the computerin real time. The operator then hasto carry out a variety of tasks simul-taneously – careful monitoring ofthe verticality of the mast and thework of the auger, its turningtorque and the depth it reaches. All

this data is conveyed to the opera-tor as well as to the onboard com-puter by the rotation table fixed tothe mast, “a real concentration ofhigh technology,” covered withsensors.As well as being used for monitor-ing the operation and calling forimmediate corrective decisions oractions, the data collected also pro-

Semi-rigid cementedinclusionsA soil reinforcing process, controlled modulus columns (CMC) aresemi-rigid cemented inclusions with distortion modules that are5 to 30 times lower than those of concrete. In practice, CMCs aremade using a special auger that pushes back the soil, and thistechnique, which does not require either vibration or driving, doesnot affect the environment. The tool is screwed into the soil to therequired depth and then brought back up with no spoil. A fluidgrout is then put into the soil by the core of the hollow auger (thespecial auger) to form a column of cemented material approxi-mately 25 to 60 cm in diameter, which withstands stresses of 10to 50 bar depending on the proportions of the mixture.

vides traceability of the work and isoften passed on to the customer ordesign firm by Ménard Soltraite-ment. Once the required depth hasbeen reached, the operator beginsthe second implementation phase,which requires just as much atten-tion, as the mortar must now hasbe incorporated in the correct pro-portions and its pressure checked.

Linked to the nature of the soil, thenumber of CMCs completed dailyvaries, but is in fact measured inmetres. On average, Mathieu Protestimates that he does 500 to 600 mper day.With machines that are performingbetter all the time – in particularguaranteeing the vertical adjust-ment of the automatic mast – theCMC operator’s job is changingand is becoming more specializedand demanding, which alsoexplains why mostly experiencedoperators are sent to the site underthe supervision of a SectionEngineer. ■

CMC OPERATOR:CONSTANT VIGILANCE

For the operator, nothingis left to chance: the positions

of the CMCs are rigorouslymarked out by the engineersand all the performance data

is recorded by the onboardcomputer.


C O M P A N Y

Employees: 66 executives,technicians andadministrators, 201 manualworkers.2004 Sales Figures:21,640 million wons(18 million euro).Managing Director: JY Kim.▼

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VITAL STATISTICS

A COMPREHENSIVEOFFERING IN SOUTHKOREAIn just over 10 years, FreyssinetKorea and Sangjee Menard havesuccessfully deployed all the know-how of the Group in Korea by signinga number of prestigious contracts

Although the presence ofFreyssinet in South Korea goes

back to September 1989, when theGroup opened a representativeoffice in Seoul, the company hasonly been formally registeredunder the name of FreyssinetKorea since 1993. Made up of fivepeople, the company was thendirected by WS Park and JY Kim,who has been Managing Directorsince 1999. Initially involved inprestressing works and structuralequipment, Freyssinet Korea cameto a significant turning point withthe Seohae bridge site in 1995. “Forthat structure,” said JY Kim, “wetook care of the prefabrication ofthe segments for the 52 spans ofthe two decks, heavy lifting, seg-ment laying, prestressing, car-riageway joints and stay cables.”This extensive service enabled thecompany to gain the status of a

PEOPLE AT FREYSSINET KOREASome of the Freyssinet Korea management team: Ji Yeong Kim (1), managing director; Byung Joo Huh (2), chief of the Reinforced Earth department; Ki Chul Won (3), marketing manager; Jong Tae Han (4), construction manager; Yoon Ik Cha (5), procurement and equipment manager; Sung Woo Kim (6), finance and administration manager; Hyun Kwon Hong (7), chief of the technical department; Sang Jin Park (8),geotechnical division manager; Seung Ik Kim (9), Structures division and technical manager.

major public works player.Finding itself in a boom situationafter this success, the companyadded repairs to its portfolio ofservices and in 1997 signed up forits first project, the strengthening ofa cantilever bridge. The companythen worked on five major projectsover the next few years: the installa-tion of the segments for a highspeed rail bridge using the MSS(movable scaffolding system); thelaunching of the Jang-An Bridgeand the installation of stay cableson the Samcheonpo, Yeong-Heungand Namdo bridges (bow-string).

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Freyssinet Korea


COMPANY

Sangjee Menard

In the Land of the Morning Calm, soil improvement works are han-dled by Sangjee Menard, an equal shareholding joint venture set upin 1992 between the Korean company Sangjee Co. Ltd and MénardSoltraitement, which handled its first project at the Honam-Oilrefinery in Yeosu in 1993 (70,000 m2 of dynamic compaction anddynamic replacement). In 1995, the work for a second phase atHonam-Oil, similar to the previous phase, and the use of theMenard Vacuum process on the platform of the Kimhae watertreatment plant (85,000 m2) confirmed the company’s status as asoil treatment specialist. From 1997, the Jangyoo water treatmentplant was handled by Menard Vacuum (70,000 m2).After restructuring the capital of the joint venture, Ménard Soltraite-ment increased its shareholding to 80% in 2003. The group is cur-rently managed by Ki Hyun Song, who is also the Chairman of Sang-jee, and by Daniel Berthier, vice chairman and Ménard Soltraite-ment’s representative in the country. In 2004 the companyachieved sales of 7 M€ ; it has 11 employees working on site andeight people at the head office. It is currently handling its largestproject yet at Kwang Yang in the south of the country (see page 22).

Support from Reinforced Earth

In the meantime, the companyonce again expanded its offering byadding Reinforced Earth andTechSpan prefabricated arches. Assoon as they were recruited, thegeotechnical engineers saw a stringof Reinforced Earth projects, whichled to Freyssinet Korea approach-ing Reinforced Earth, the Group’sAustralian subsidiary, in order tobenefit from its expertise and sup-port for staff training for the firstdesigns. Australia also came to theaid of Korea when the first ordersfor TechSpan arches were taken in2005 for the construction of twocovered trenches on the Cheong-won-Sangjiu and Taebaek-Seohak

motorways. At the same time, thedeployment of structural skills con-tinued with the introduction offloor prestressing (Samsung LeeumMuseum) in 2003, followed by theCohestrand strand and deviationsaddles, which will be imple-mented in 2006. ■

PEOPLE AT SANGJEE MENARDKi Hyun Song, chairman of Sangjee Menard;Daniel Berthier, vice chairman of Sangjee Menard andMénard Soltraitement representative for South Korea.

1. Between 1998 and 2000,Freyssinet Korea assisted in thebuilding of the Seohae bridge,a 7,310 m structure acrossthe bay of Asan, by designinga self-launching truss for theconstruction of the spans andsupplying and installing theprestressing for the pylons andstay cables.3. Between 1999 and 2000,Freyssinet Korea carried outall of the superstructureconstruction, prestressing andlaunching work on the 525 mJang-An bridge, 100 km south-west of Seoul.2. In soils, Freyssinet Korea isto complete its first TechSpanarch project in 2006 on theCheongwon-Sangju motorway.The structure will require theinstallation of 524 half-arches.

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H I S T O R Y


1950

FROM JACKS TO COMPUTER-Freyssinet, a pioneer in the use ofjacks for handling and lifting, hasplayed an active role in thedevelopment of this technology.Coupled with an IT system, thistechnology now allows formanoeuvres to be carried out withmicrometric precision.

1930/1940

In 1932, to strengthen the founda-tions of the marine terminal at LeHavre, which were subsiding by 1to 2 cm per month, EugèneFreyssinet suggested the installa-tion of new piles using piston-bor-ing jacks. At that time, jacks wereonly used for organizing or reor-ganizing internal structural loads.

Eugène Freyssinet invented flatjacks in 1938. For the first time heused them on the Beni-Bahdeldam in Algeria, and then for theconstruction of the bridges overthe Marne in 1946 to adjust thethrust of the depressed archesusing both flat jacks and wedging.

1960

1970

Keeping bridge clearances in motorways afterreballasting impose sometimes to raise the struc-tures, therefore exceeding the stroke of flat jacksand thus requiring the use of mechanical jacks.The change in bridge clearances due to motor-way construction saw the introduction ofmechanical jacks, which had greater stroke thanflat jacks. This was also when Freyssinet carriedout the first ’step by step’ lifting during the con-struction of the Libourne water tower. The1.000 m3 vessel was constructed and cast on the ground, then lifted as thetower was built using 24 75 t jacks with a stroke of 20 cm placed on pil-lars composed of match-cast joints elements. Other structures of thistype were built in the same manner such as in Saint-Lô (Manche) and inthe Middle East. The technique remained rather rudimentary: an equalvolume of oil was injected into each jack. Manual adjustments wererequired to correct any discrepancies.

On the construction site of thestorage ring for the Orsay linearaccelerator, built during the 1960s,the company supplied flat jacks tolevel the structure. During con-

struction these structures weremastered with excellent accuracy.This usage opened a newapproach to using jacks: in addi-tion to controlling forces andstrain, the Stup engineers turnedtheir attention to the movementand displacement of horizontaland vertical loads. The companywas involved in several projects ofthis type, in particular the dis-placement of the Abu Simbel tem-ples in Egypt during the construc-tion of the Aswan High Dam overthe Nile in 1967, and then inadmittedly less spectacular proj-ects lifting numerous road bridgestructures for the bearings to bechanged.

In 1956, the business,which was then called Stup(Société technique pour l’utilisa-tion de la précontrainte - Techni-cal company for the use of pre-stressing), specialized in the reor-ganization of stressing for struc-tures and flat jacks to carry out lowamplitude movements of thosestructures. This method strength-

ened the bells of the La Chaise-Dieu church in Haute-Loire, amonument dating back to thefourteenth century. During thisperiod, the company played anactive part in the development ofhandling and moving loads bystudying the launching and shift-ing of straight beams for bridgeconstruction.

HISTORY


The growing interest in construc-tion on the ground and putting thestructure in place at a height gaverespectability to jack lifting, whichbecame a recognized constructionmethod used by professionals. In1982, Freyssinet pioneered thesynchronized plant technique,which was perfected by PierreGuinard. An equal volume of oilis injected into eight jacks simul-taneously; electronic displaysassembled on the equipment

show displacement readings, mak-ing it possible to act on each chan-nel to make corrections. The Cipecsubsidiary developed its own sys-tem. In 1989, Freyssinet was calledin to level eight hammerhead pierson the site of the Barrières duHavre viaduct, using 12 simultane-ous lifting channels. The first com-puter-aided lifting machine wasused to carry out this delicateoperation. A computer automati-cally halts the process in the eventthat the tolerance is exceeded andadjusts the level position. Usingthis revolutionary approach, thesystem relies on the processor’slow resolution speed, which con-trols the accuracy within a mil-limetre. The system quickly estab-lished itself, paving the way for thedevelopment of cable and jack lift-ing, which is more effective andpopular with construction compa-nies. In 1983, the lifting of theSaint-Quentin-en-Yvelines watertower vessel was the first in a longseries.

1980

AIDED LIFTING: THE RISE OF LIFTING

2000

In 1992, Freyssinet’s engineersworked on the development of alifting machine controlled by a pro-grammable logic controller (PLC).Since then, tasks have been distrib-uted as follows: a processor carriesout the calculations while a PLCcontrols the functions. Errors dueto the opening and closing time ofthe solenoid valves have beenreduced. Speed has increased con-siderably and accuracy is nowwithin a tenth of a millimetre forboth lifting and lowering. Eachmachine comprises several lifting

channels and can be connected toother machines that it monitors,allowing for infinite combinations.The use of sensors further improvesthe system’s performance, whichno longer requires a fixed point ofreference on the ground to locatepositions in space. In 1996, 240jacks synchronized using this sys-tem were used to decentre the rein-forced concrete cover slabs onbuilding F at Paris Charles deGaulle (Roissy) Airport to deformthe steel hanger structure withoutbuckling the cover slabs.

1990

Developing the heavy lifting activity (such as the lifting of the roof of the Cam-pione Casino in Switzerland – Photograph above) Freyssinet strengthened itsoffer with the acquisition in 2004 of the Swiss company Hebetec, a specialistin lifting, lowering and moving heavy loads, to expand its range of services.

Africa andmiddle-East

EgyptFreyssinet EgyptGizaPhone: (20.2) 345 81 65Fax: (20.2) 345 52 37

KuwaitFreyssinet International & Co.SafatPhone: (965) 906 7854Fax: (965) 563 5384

South AfricaFreyssinet 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

United Arab EmiratesFreyssinet Middle East LLCDubaiPhone: (971) 4 286 8007Fax: (971) 4 286 8009

Freyssinet Gulf LLCDubaiPhone: (971) 4 286 8007Fax: (971) 4 286 8009

America

ArgentinaFreyssinetTierra Armada SABuenos AiresPhone: (54.11) 4372 7291Fax: (54.11) 4372 5179

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

CanadaReinforced Earth CompanyLtdMississaugaPhone: (1.905) 564 0896Fax: (1.905) 564 2609

ChileTierra Armada S.ASantiago de ChilePhone: (56.2) 2047 543Fax: (56.2) 225 1608

ColombiaStup de ColombiaBogotaPhone: (57.1) 236 3786Fax: (57.1) 610 3898

Tierra Armada LtdaBogotaPhone : (57.1) 236 3786Fax : (57.1) 610 3898

El SalvadorFessic SA de CVLa LibertadPhone: (503) 278 8603Fax: (503) 278 0445

GuatemalaPresforzados Técnicos SAGuatemala CityPhone: (502) 2204 236Fax: (502) 2500 150

MexicoFreyssinet de México SA de CVMexico DFPhone: (52.55) 5250 7000Fax: (52.55) 5255 0165

Tierra Armada SA de CVMexico DFPhone: (52.55) 5250 7000Fax: (52.55) 5255 0165

United StatesDGI - MenardBridgeville, PAPhone: (1.412) 257 2750Fax: (1.412) 257 8455

Freyssinet LLCChantilly, VAPhone: (1.703) 378 2500Fax: (1.703) 378 2700

The Reinforced EarthCompanyVienna, VAPhone: (1.703) 821 1175Fax: (1.703) 821 1815

VenezuelaFreyssinetTierra Armada CACaracas DFPhone: (58.212) 576 6685Fax: (58.212) 577 7570

Asia

Hong KongFreyssinet Hong Kong LtdKwung Tong - KowloonPhone: (852) 2794 0322Fax: (852) 2338 3264

ReinforcedEarth Pacific LtdKwung TongPhone: (852) 2782 3163Fax: (852) 2332 5521

IndonesiaPT Freyssinet Total TechnologyJakartaPhone: (62.21) 830 0222Fax: (62.21) 830 9841

JapanFKKTokyoPhone: (81.3) 5220 2181Fax: (81.3) 5220 9726

TAKKTokyoPhone: (81.44) 722 6361Fax: (81.44) 722 3133

MalaysiaFreyssinetPSC (M) Sdn BhdKuala LumpurPhone: (60.3) 7982 85 99Fax: (60.3) 7981 55 30

Ménard Geosystems Sdn BhdSubang Jaya SelangorPhone: (60.3) 5632 1581Fax: (60.3) 5632 1582

Reinforced EarthManagement Services SdnBhdKuala LumpurPhone: (60.3) 6274 6162Fax: (60.3) 6274 7212

PakistanReinforced Earth Pvt LtdIslamabadPhone: (92.51) 2273 501Fax: (92.51) 2273 503

SingaporePSC Freyssinet (S) Pte LtdSingaporePhone: (65) 6899 0323Fax: (65) 6899 0761

Reinforced Earth (SEA) Pte LtdSingaporePhone: (65) 6316 6401Fax: (65) 6316 6402

South KoreaFreyssinet Korea Co. LtdSeoulPhone: (82.2) 2056 0500Fax: (82.2) 515 4185

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

ThailandFreyssinet Thailand LtdBangkokPhone: (66.2) 266 6088/90Fax: (66.2) 266 6091

VietnamFreyssinet VietnamHanoiPhone: (84.4) 826 1416Fax: (84.4) 826 1118

Europe

BelgiumFreyssinet Belgium NVVilvoordePhone: (32.2) 252 0740Fax: (32.2) 252 2443

Terre Armee Belgium NVVilvoordePhone: (32.2) 252 0740Fax: (32.2) 252 2443

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

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

FreyssinetInternational & CieVélizyPhone: (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

PPCSaint-RemyPhone: (33.3) 85 42 15 15Fax: (33.3) 85 42 15 14

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

FyromFreyssinet BalkansSkopjePhone: (389.2) 3118 549Fax: (389.2) 3118 549

GermanyMenard Dyniv GmbHSeevetalPhone: (49) 4105 66 480Fax: (49) 4030 23 98 25

Bewehrte ErdeSeevetalPhone: (49) 4105 66 48 16Fax: (49) 4105 66 48 66

Great-BritainCorrosion ControlServices LtdTelfordPhone: (44.1952) 230 900Fax: (44.1952) 230 960

Freyssinet LtdTelfordPhone: (44.1952) 201 901Fax: (44.1952) 201 753

ReinforcedEarth Company LtdTelfordPhone: (44.1952) 201 901Fax: (44.1952) 201 753

HungaryPannon Freyssinet KftBudapestPhone: (36.1) 209 1510Fax: (36.1) 209 1510

IrelandReinforced EarthCompany Ireland (Ltd)KildarePhone: (353) 45 431 088Fax: (353) 45 433 145

ItalyFreyssinetTerra Armata SRLRomePhone: (39.06) 418 771Fax: (39.06) 418 77 201

NetherlandsFreyssinet Nederland BVWaddinxveenPhone: (31.18) 2630 888Fax: (31.18) 2630 152

Terre Armée BVBredaPhone: (31.76) 531 9332Fax: (31.76) 531 9943

NorwayA/S SkandinaviskSpennbetongSnarøyaPhone/fax : (47.67) 53 91 74

PolandFreyssinet Polska Sp z.o.o.MilanówekPhone: (48.22) 724 4355Fax: (48.22) 724 6893

PortugalFreyssinet - Terra ArmadaLisbonPhone: (351.21) 716 1675Fax: (351.21) 716 4051

RoumaniaFreyrom SABucharestPhone: (40.21) 220 2828Fax: (40.21) 220 4541

RussiaFreyssinetMoscowPhone: (7 095) 7475 179Fax: (7 095) 7475 179

SpainFreyssinet SAMadridPhone: (34.91) 323 9500Fax: (34.91) 323 9551

Tierra Armada SAMadridPhone: (34.91) 323 9500Fax: (34.91) 323 9551

SloveniaFreyssinet AdriaAjdovscinaPhone: (386) 5 36 90 331Fax: (386) 5 36 90 200

SwedenAB SkandinaviskSpaennbetongMalmöPhone/fax : (46.40) 98 14 00

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