Footbridge over the Cher N°210 - January - Freyssinet

France

Footbridgeover the Cher

JANUARY / APRIL 2001 - No. 210

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Spain

Renovatedchurchesp. 18

Co

nte

nts

Contents

2Freyssinet magazine January / April 2001 - No. 210

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

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Cher footbridgep. 8

United Kingdom

High speedlinep. 13

EUROPE

Freyssinet Magazine, 1 bis, rue du Petit-Clamart 78148 Vélizy Cedex - France. Tél. : 01 46 01 84 21. Fax : 01 46 01 86 86.Site Internet : www.freyssinet.comPublication manager:Claude Lascols. Contributed to this issue: Raja Asmar, Somnath Biswas, Laure Céleste, StéphaneCognon, Bertrand Garin, Christophe Houix, Marc Lacazedieu, Jean-Paul Marquet, Paul McBarron, Yvonne McDonald,Milena Mora, Sylviane Mullenberg, Tomas Palomares, Isabelle Pessiot, Bertrand Petit, Ahmed H. Rashwan, Jean-MichelRomagny, Wong Soon Shing, J.Y. Jang. Artistic management: Antoine Depoid. Layout: Grafik Tribu. Translation: Netword. Project leader: Stéphane Tourneur. Editorial secretariat: Nathalie Laville. Photos: ClaudeCieutat, Lim Jeong Eui, stt, Francis Vigouroux, Freyssinet Library. Cover page: Footbridge on the Cher in Tours, photo FrancisVigouroux. Photo-engraving: Trameway/Grafik Tribu. Printing: SIO.

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AMERICA

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Contents


ASIA

HONG KONGFreyssinet Hong Kong LtdKowloon TongPhone: (852) 27 94 03 22

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France

Restoration of theRhine-Rhone canal

p. 17

Egypt

Two electricitypower stationsp. 14

Egypt

Construction of cement factoryp. 19

Malaysia

Penangbridgep. 16

Taiwan

Award forConstruction Automation

p. 19

Interview

Tunnels, bridgesand architecture:

a new visionp. 4

Freyssinet APTO (M) Sdn BhdKuala LumpurPhone: (60.3) 282 95 88/75 88/

05 88/96 88Fax: (60.3) 282 96 88

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TAIWAN Freyssinet Taiwan EngineeringCo, LtdTaipei Phone: (886.2) 274 702 77Fax: (886.2) 276 650 58

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d

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Freyssinet Magazine: Architects appear to be more closelyassociated with the construction oflarge bridges and viaducts nowadays.Is this a new phenomenon?Alain Spielmann: In general, French tradi-tion has always been that designers and archi-tects work closely together on major construc-tion sites. But nowadays, it is true one result ofcompetitions is that they are more systematical-ly called upon to contribute to all types of con-struction programs, and are more frequentlymentioned. Architects have been in the repairand reinforcement activity for many years, forexample particularly for Paris bridges.I myself was involved in the restoration of Parisbridges in the 1970s, with the objective of mak-ing the structure and the frame clearly visible.Note that the repair activity will become morewidespread, as structures are brought up to stan-dards or their functions are changed. Architects'studies and proposals bring a renewed approach,in structural engineering.

What is the role of the architect now?A. S.: Architects still have the same freedomthat they enjoyed in the past. However in myown experience, I feel much freer because Ihave a better knowledge of my work. This hasnothing to do with external constraints, butrather with constraints that I have set myselfand the new means available to us. We can nowuse extraordinary high performance tools forcalculations and construction that we couldnot use before, thus widening our field ofaction. The role of the architect is to encourageman to think. I am in favour of an uplifting

Interview

4Freyssinet magazine

Tunnels, bridges andarchitecture: a new visionAlain Spielmann is the architect for the footbridge over the Cher, in Tours. He talks to us about his profession today, and about the most recent architectural changes in structures.

January / April 2001 - No. 210

architecture, like the footbridge over the Cherin Tours suspended on a single cable with itsred tubular and inclined towers, platform andwooden handrail.

How are the engineering and archi-tectural businesses complementary?A. S.: Our businesses share their enthusiasmfor construction. What has changed is that newgenerations of architects and engineers want toexpress themselves, and at the same time, thepublic at large would like to live in an environ-ment that makes it feel good. We are facing ademand that we need to understand, decryptand explain. Our engineers must be creative intheir own field and have the means to do so.They also need to be able to take account of thephysical realities of materials and the psycho-logical needs of men in order to develop specif-ic concepts, forms, project desires without anyarchitectural hindrance to the imagination. Thesubject is exciting precisely because it is diffi-cult. We need to cooperate with engineers, uniteour passions and our desires to build, and tojoin forces with them.

What architectural changes are beingmade in structures?A. S.: In France, traditional age-old construc-tion techniques are still frequently used in con-struction. We frequently find ourselves needingto deal with complicated problems due to oldtechnologies, old fashioned techniques and gen-erally being late in introducing the use of sometechniques. Therefore, there is an extremely bigdifference between buildings in which industri-al means are used and buildings built by crafts-

Alain Spielmann, DPLG architect: "The role of thearchitect nowadays is to forceman to think. I am in favour of an uplifting architecture."

Viewpoint

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Interview


men, in which practices that have proven theirvalue are used, but in which progress is muchslower. On the other hand, we have a highlysophisticated concentration of means and tech-nological development for the bridge construc-tion industry, and this is not the case every-where in the world. Note also the differentscales. Spans in buildings vary from 5 to 7 m,whereas bridge spans can reach several hundredmeters. Therefore two quite different approach-es are necessary.In any case, the trend in both fields is to reducethe weight of the structures. Lighter weightmaterials are used, with more powerful liftingequipment and more highly specialized person-nel. Today's and tomorrow's structures are andwill really be lighter, thinner, more transparent,more comfortable, but also sounder and willblend better into their environment. I thinkthey will be more cheerful and brighter, morecolorful with more fantasy, making a break withthe current frequently somber fashion. We aremoving towards structures that will be moreimaginative while respecting the environment,and will have better sound and thermal quali-ties… without introducing extravagant expenses.

You recently talked about "construct-ed poetry"?A. S.: Constructed poetry is an objective to beattained. It is a correspondence between alifestyle and acquired know how that we trans-late into forms with our hands. I call that con-structed poetry, and I think this expression isparticularly meaningful in the construction of abridge such as the footbridge over the Cher inTours. The general public spontaneously recog-

nizes it as such and feels it. This is a vital need,something common to everyone everywhere inthe world, a common denominator.

How is it applicable to a bridge likethe Cher footbridge?A. S.: It was necessary to solve a problem, tobuild a bridge within a very short time within avery tight budget. After my experience withconstruction of the Blois bridge in which wewere faced with foundation problems, I decidednot to use supports in the Cher. Maintainingthe tradition of builders in the past who hadbuilt suspension bridges over the Loire, I chosethe same type of structure with a 235 m span,which was an economic solution. Therefore weworked with the engineers to design a structurederived from the structure designed by theengineer Mr. Le Ricolais in the form of a bracedtriangle. It is a simple structure with two V-shaped towers, a suspension cable and two235 m lateral cables . We built a rigid structurefrom flexible materials, the cables. The result isa footbridge that blends well into its surround-ings. We attempted to solve the problem and wefound a solution that combines finesse of thebridge and the use of easily available materials.Our work blends into the present day context,and is a modern means of expression.

Is the belvedere in the middle of thefootbridge your personal style?A. S.: It has become so in time. I built belved-eres on the bridges over the Allier, in Laval,in Blois, etc. I always thought that a building,bridge, construction, etc. should perform sever-al different functions and be versatile. I included

elements that would contribute towards helpingpeople feel a part of the setting and appreciateit, to highlight its poetry. The belvederes andadditional elements incite the public to taketheir time and really look at the bridge. Theyperform their function, and help people to feelcomfortable on the bridge.

Architects have been in the repair and reinforcement business for many years, particularly for historic monuments like the Genil bridge in Spain that Freyssinet teams recently restored.

"In the building industry, there is a world of difference between buildings built usingindustrial means (like the Telekom Malaysiabuilding) and buildings built by craftsmen."

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South Korea

Seohae bridge

United Kingdom

MedwayBridgeStrengthening

In brief

Repair and consolidation works on the bridge over the river Medway had become urgent.This bridge was built in 1962, and needs to be upgraded to satisfy new roads and bridgesstandards in Britain and to carrynew traffic flows from the coast due to widening the M2 motorway. The contract included the use of Freyssinet's C range anchoragesystem for external prestressingwith unbonded strands and priorinjection of cement grout (for thefirst time in the United Kingdom), to prestress the 95 m access spans and the 61 m long main span. Maunsell (the client), theHighways Agency (the consultingengineer), and Edmund Nuttall (the main contractor) appointedFreyssinet UK to install 96 tendonsin the four quadrants of the bridge.

Freyssinet magazine 6 January / April 2001 - No. 210

Seohae bridge is about sixtykilometers from Seoul and is the longest bridge in Korea. It was opened to traffic on November 92000. The 7310 m long bridge joins Pyongtaek to Danji and carries six traffic lanes. Freyssinet supplied and installed the prestressing and the bridge equipment for someaccess spans, and placed the staycables for the main bridge (seemagazine No. 203, November 1998).The 990 m long main bridgecomprises an 870 m cable stayedpart with a 470 m central span. The deck is supported by two layersof cables each with 72 stay cablesanchored at the top to two 180 m hightowers. The stay cables fitted withDGD dampers are composed ofunbonded strands in galvanizedducts. They are tensioned usingFreyssinet's patented Isotension®

process and are inserted inside adouble spiral duct to countervibration phenomena in this areaaffected by typhoons.

Gatwick airportuses a passengertransit system on a dedicated linecomposed ofshuttles operatingbetween the Northand Southterminals. Thetrack is elevatedand passes overthe A23 motorwayon a viaduct. The viaduct iscomposed of acontinuous box

girder with two 82 m long cantilever spans.The structure is supported on bearings on

each abutment and on the central pier.Freyssinet replaced the two main guidedsliding bearings on one abutment, fourviaduct bearings, and repaired the otherthree. The contract included the design and placement of a temporary supportsystem by means of jacks to raise the A23 bridge. The system was required to support high loads and absorb the dynamic reactions of the bridge caused by trains passing over every two minutes. The design also allowed for rotating and leveling the structure to realign the tracks between the abutments and the deck. Freyssinetdesigned and made all the new stainlesssteel bearings weighing 350 kg, andincluding anti-vibration elements.

Kosovo

Bridge repairFreyssinet has widened the central pier, reconstructed the slab and pavements made of concrete and replaced the bearings and expansion joints, on the one hundred meter long Mitrovica bridge. Apart from these structuraloperations, the works also include the placement of additional architectural elements such as viewpoints on the bridge, the supply and placement of lighting, bank access steps and the construction of two decorative arches. At the same time, Freyssinet is working on two other bridges in the Pristina region. Milosavobridge that was completelydestroyed during the war, and Vrani Do that was partiallydestroyed, are being rebuilt usingprecast elements.

Replacing bearings on an airport viaduct

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In brief

7 January / April 2001 - No. 210Freyssinet magazine

Venezuela

Reinforced Earthwalls at PradoHumboldt Park The Venezuelan population is becomingmore urban. This change is the reasonwhy construction companies are buildingresidential areas around the periphery of towns. These areas very often include steep and irregular topography on whichefficient, safe, fast and economicconstruction methods have to be found to stabilize the fill. The Prado HumboldtPark residential area is a good illustration.Fill at an average slope had to bestabilized to retrieve land, and accessramps had to be built for road traffic and for pedestrians, as part of thiscomplex including six apartment towerblocks. The works were done usingReinforced Earth walls. The total surface area of walls, between Main Street and the various buildings, was 1055 m2.

India

Retaining walls for access ramps

HomageSir Alan Harris

Australia

Burnley TunnelThe Burnley Tunnel is 3.4 km long, carriesthree traffic lanes in each direction, and forms part of the City Link project, a Melbourne expressway. The D-shapedtunnel was drilled to keep a minimumcover of 12 m of moderately weathered tofresh mudstone under the Yarra River. Theprimary support system used shortcrete,rock bolts, and where necessary steel setsduring excavation. After excavation, awaterproof membrane and concrete lining,300 to 450 mm thick, completed thestructure. Before that, the raft had to bestabilized by ground anchors andgrouting. Austress Freyssinet were part ofthe remedial work team for the project andwere awarded the contract for the detaileddesign, supply, installation and stressingof 1800 permanent rock anchors. Anchorswere installed at a spacing of 1100 mmand drilled 10 m into suitable rock, andconsisted of seven 15.2 mm diametertendons and 40 mm diameter Macalloybars.

The engineer Alan Harris, the founder of theHarris & SutherlandCompany, knightedin 1980, diedrecently at the ageof 84 years. Hehad been awardedthe French Croixde Guerre for his

actions during the Second World War.After the war, he joined EugèneFreyssinet at the STUP. The company hired him, and heacquired theoretical design experience

and practical experience on site. Hereturned to London in 1949 asFreyssinet's Chief Engineer and GeneralManager of the Prestressed Concretecompany that operated under a license.Alan Harris designed many structuressuch as silos and bridges, etc., and wasparticularly involved in education andthe institutions.He was President of the Institution of Structural Engineers, vice-president of the ICE and taught concretetechniques as Professor at ImperialCollege. We would like to express our profound sympathy to his wife,Lady Harris, and their two sons.

Like all other large cities, Mumbai (formerley Bombay) is facing serious transport difficulties that have beencontinuously increasing in recentyears. In cooperation with thegovernment of Maharashtra, theMaharashtra State RoadDevelopment Corporation Ltd(MSRDC) decided to build 50 road bridges and overpasses in the town. Reinforced Earthretaining walls were chosen for the construction of bridge

access ramps. Differentarchitectonic surfaces were used,varying from conventional plainpanels to panels with diamond or ribbed patterns. The AIMIL-TAIjoint venture has already constructed15 000 m2 of Reinforced Earth walls in Mumbai for the Chedda Nagar,Konkan Bhawan, Aarey-Goegaonroad bridges, the Goregaon-Mulundbypass, the SION Roundabout and extension of the Chembur to Mumbai link. These bridges are now open to traffic.

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France

Main figures

• Footbridge length: 235 m.

• Tower height: 35 m.

• Diameter of steel tubes for tower: 812 mm.

• Tower inclination: 69°.

• Deck width: 3.1 m.

• Number of segments in the deck:

eleven 20 m elements.

dige

st

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France


A new 235 m span

footbridge has recently

been opened in Tours.

It makes use of a mod-

ern and uplifting architecture giving

the impression of soaring effortless-

ly over the Cher.

digest

Cher footbridge

Suspended bridge

The Cher footbridge is a lightweight braced triangular shaped structure, derived from the footbridge constructedby the French engineer, Mr. Le Ricolais.

GB 210 12/04/01 15:05

Since the end of the year 2000, a footbridgehas connected the center of the City ofTours to the quickly expanding Deux-

Lions district occupied by businesses, homes,leisure centers, schools and universities. This235 m span footbridge suspended from a singlecable crosses over the Cher without any pier orother support on the islands over which it pass-es. Lateral cables are provided for dynamic sta-bility of the assembly.The structure comprises harmonious colorsand a variety of materials including oven-lacquered guardrails, a wooden handrail andplatform, and red towers, and is illuminated atnight to form an outstanding landmark of thetown. The circular lookout in the middle of thefootbridge offers pedestrians a new viewpointover the islands that have remained in their nat-ural state, and on the river itself.

Lifting of the towers

The human, technical and industrial meansused for the main elements of the bridge (thetwo towers, the support cable, the two lateralcables and the deck) are typical of what isrequired for a large project. The works startedon both sides of the Cher by the construction oftwo concrete foundations anchored by 27m longmicro-piles to support the stands of the bridgetowers, and a back foundation also anchored by27 m long micro-piles for the suspension cable,and another two temporary micro-piles to resistforces due to deck launching operations. Theforward foundations were connected to eachother by a beam prestressed by Macalloy bars toresist horizontal forces.The tower legs were then placed. They are 35 mhigh and composed of 812 mm diameter steeltubes prefabricated in the workshop and weldedtogether. The legs were transported to site bytruck and welded together to form an inverted Vwith a diaphragm near the top over which thesuspension cable passes. The tower is hinged atthe bottom, and was lifted using a 200 t mobilecrane. This very tricky operation was done in

Freyssinet magazine January / April 2001 - No. 210

France

10

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France


MORE THAN 20 YEARS EXPERIENCE IN CONSTRUCTION AND REPAIRS OF FOOTBRIDGES

West-Kowloon, Hong-Kong (1997)

Bandar-Sunway,Malaysia (1993)

Cotton Tree Drive,Hong-Kong (1980)

Ville-sur-Haine, Belgium (1988)

Grand-Tressan, France (1989)

Collège in Lyon, France (1996)

Brystrzyca, Poland (1999)

Illhof, France (1980)

St Georges in Lyon,France (1999)

Marc-Seguin in Tournon,France (1999)

Pas-du-Lac, Saint-Quentin-en-Yvelines,France (1992)

Other realisations:Poplar Walkway, Great Britain (1992) ; Pyrmont, Australia (1993), RW 16 in Rotterdam, Holland (1994) ; Izmir-Güzelyali, Turkey (1997) ;Indooroopilly, Australia (1998) ; Chartrouse, France (2000) ; footbridge over the Cher in Tours, France (2001) ; footbridge overthe Sarre in Sarreguemines, France (2001) ; and many others...

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12 January / April 2001 - No. 210Freyssinet magazine

half a day under the permanent control of a sur-veyor. During lifting, it was essential that thepulley block should remain on the longitudinalaxis of the footbridge to avoid unbalancing thestructure. The tower was raised to 69° and heldin place by temporary struts. The tower inclina-tion was calculated with a slight backwards tiltto compensate for the movement that wouldoccur later due to the weight of the deck.Temporary strands were then installed betweenthe two towers to place the main cable and theman-lift.

Placement of the main cable

A T15 strand was launched from one bank tothe other between the tops of the towers, with asag of 16 m. Three other T15 strands were theninstalled and were used to place a self-poweredsuspended man-lift, from which works could bedone on the cables and hangers. This man-lift

was pulled by a tyrack and was remote con-trolled. An onboard generating set suppliedpower for raising or lowering the man-lift.The four 60 mm diameter 320 m long cablesforming the main cable were unwound fromreals with hydraulic brakes and pulled by a 3 twinch from the opposite bank. A system com-posed of rollers and pulley blocks was used topass the end fitting over the saddle at the top ofthe tower. The suspension cable is assembled by30 collars at 7.5 m intervals.

Launching the deck

The deck was launched by applying a tensionof 10 t to two groups of cables comprising6 strands, between the suspension cable anchorfoundations. Before this, the deck was assem-bled by 20 m segments, and elements were car-ried by crane to the launching area composed ofU-rods and walker pads. A hydraulic wheelsdevice was bolted to the abutment and was usedto tilt elements on the strands. The pads withgrease combs inserted between the deck struc-ture and the strands facilitated sliding. A 3 twinch on the opposite bank pulled the deck, anda 2 t retaining winch was fixed on the launchingarea.The deflection of the strands at the center of thestructure was 4 m during launching. Once theelement had reached its position, four hydraulicpullalongs installed on the deck and supportedon the suspension cable were used to hoist theelement to its geometric position. The finalhangers were installed and the loads were trans-ferred to them. The lift height at the center ofthe structure was 9 m, thus forming a genuinetrampoline; the original slope of the bridge (3%)was restored during launching of the other elements. The eleven approximately 20 m longsteel segments were prefabricated in the plantand then pulled and assembled in sequence.The platform was screwed into place as deckconstruction progressed. It is composed of 3.1m

long, 0.14 m wide and 0.03 m thick Angelin-Vermehlo tropical hardwood planks with an"anti-vertigo " profile and a slip resistant surface.At the same time, the guardrails (oven-bakedwith an Angelin-Vermelho wood handrail) andlights were fixed to the deck.The works were completed by the placement ofthe two final lateral cables launched from thebank to provide complete transverse stability. Ateam of mountaineers was hired to tighten theside collars and the hangers for these eccentriccables above the Cher.

ParticipantsClient: SET (Société d’Equipement de laTouraine- Tourain Development Company).Contract manager: Scetauroute (agent) and the architec Alain Spielmann.Contractors: Freyssinet France (agent) et Matiere.

France

The side collars and hangers were tightened by a team of mountaineers above the Cher.

The deck was placed by incremental launchingof the segments using a tensioned strandssystem between the banks of the Cher and pads with greased combs.

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United Kingdom


TechSpan® arches

T he new line is divided into two parts. Thefirst 74 km long part links the Tunnel to Fawkam Junction on the south bank

of the River Thames and should be opened topassengers in October 2003. The second phaselinks Southfleet to Saint Pancras station in theheart of London and will be opened to Eurostartrains in December 2006.On this line, contract 420 covers 20 km in theheart of Kent from Boxley to Lenham Heath.Two cut and cover tunnels were constructedclose to the villages of Hollingbourne andSandway. The initial proposal for these twostructures was to construct the tunnels as in-situreinforced concrete box structures. However,following a Value Engineering exercise theReinforced Earth Companies proposal to useTechSpan® arch system was accepted.

TechSpan® system, the economic solution

The two tunnels are built by assembling twoprecast concrete TechSpan® units with a width of14 m and a clear height of 8.5 m. The longertunnel (Hollingbourne) is 360 m long, andSandway tunnel is 170 m long. Backfill cover tothe crown of the arches ranged from 0.5 m up to5.5 m at the deepest section. The line crosses exist-ing roads at Eyhorne Street (Hollingbournetunnel) and Headcorn Road (Sandway tunnel).For this reason the tunnels were built in twophases, so that temporary road diversionscould be setup over the partially completedstructures. Finite Element Method Analysiswas used to study the behavior of the tunneland optimize material quantities, the thicknessof the arch thus being reduced to 325 mm.The TechSpan® foundations are supported on

3.5 m and 4 m wide independent strip founda-tions. These foundations were built directly ona dense sand deposit (Folkestone Beds Sand).The portals to the tunnels were formed usingReinforced Earth™ precast concreteTerraClass™ facing panels to form the head-walls and wing walls.Construction of the first 170m of Hollingbournetunnel was started in April 2000 and completedjust four weeks later. Completion of the twotunnels is planned for March 2001. This "highspeed" construction and optimal use of materi-als makes this solution particularly economic.

ParticipantsClient: Union rail.Contract manager: Hochtief – Norwest Holst JV.Project management: Rail Link Engineering (RLE).Design: Rail Link Engineering (RLE).Specialized contractor: Reinforced EarthCompany Ltd.

High speed line

Channel Tunnel Rail Link provides a high speed line (300 km/h) that will eventually link London to the Channel tunnel terminal near Folkestone, in Kent.

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14 January / April 2001 - No. 210

Soil improvement

Egypt

Freyssinet magazine

T here is a close relation between both pro-jects, East Port Said Power Plant and SuezGulf Power Plant, since EDF international

is constructing two identical electricity powerstations with a unit capacity of 341 MW (com-bined fuel oil and gas). One of the power stationsis located in the Sinai desert, and the other at theconfluence between the Suez canal and the RedSea. Both sites are being built at the same timewith one six months in advance of the other,and both are in the form of a B.O.T. (Built,Operate, Transfer) concession; the power stationswill subsequently be retroceded to the EgyptianElectricity Authority (EEA).

Two distinct techniques

The construction of the foundations for the twoprojects makes use of different techniques. A20 m thick clay layer at a depth of about 10 munder the future power station platform wasdetected in Port-Saïd. The presence of this high-ly compressible clay subject to consolidationcould cause high negative friction on the foun-dation piles in the long term, thus making theworks tricky and expensive, with the use of tub-ing over the first 30 meters to separate the pilesfrom the surrounding soil.Menard Soltraitement was called in by the pro-ject engineer (EDF CNET) and suggested a solu-tion to EDF that consisted of improving the soilacross the entire site. The plan is to compact thesoil over a period varying from four to ninemonths to achieve a degree of pre-consolidationequivalent to what would have occurred after20 years under the power station load if no priorworks were done. This was achieved by the con-struction of prefabricated drains throughout thethickness of the clay layer and the application of

an overburden consisting of temporary fill. Withthis treatment, most of the originally plannedpiles were eliminated and the buildings weresupported directly on the surface foundations.Furthermore, there is no negative friction on theremaining piles.

Pre-consolidation

The design of the drain network and the depthof overburden was adapted to each situationdepending on the final load and the allowablepre-consolidation time. The final load is between1 t/m2 and 20 t/m2, the depth of the verticaldrains is 32 m at a square grid varying from 1 to1.37 m. The pre-consolidation time was fromfour to nine months and the overburden depthwas between 8.5 and 16 m. A total of 53 000drains representing a total length of more than1 600 000 meters were installed in less than threeand a half months by means of two speciallydesigned machines working on two shifts. Morethan 750 000 m3 of fill was then put into place topreload the site.Soil consolidation was checked by means of amonitoring system composed of settlementplates, pore pressure sensors and slope stabilitysensors (extensometers and inclinometers). Thismonitoring system is still in place and will beused until the middle of the year 2001.A first area has already been released for con-struction of the civil works. The observed con-solidation in this area caused a settlement ofmore than 1.3 m under 8.5 m of overburdenplaced for four months with drains on a 1.37 mgrid. The settlement at the moment in the oiltanks area where the load is highest is more than2 m under 11.5 m overburden, after four monthsat a 1 m grid.

EDF International is currently building two power stations in Egypt.This project required soil improvement by Menard Soltraitement.

Two electricitypower stations

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Egypt

15

Consolidation principle

The compression of sandy soils under a given load (for example a building) takes place as soon as this load is applied. The result is a settlement called an "immediate settlement" that can be assumed to be elastic for all practical purposes. However, buildings founded on clay soils settle over a long period at a gradually decreasing rate until they stabilize. This long term settlement of clay soils under constant load is called "consolidation settlement". This phenomenon is explained by the fact that the porepressure of water in the soil must decrease before the soil can settle.Since clay soils are only very slightly permeable, this water can only be evacuated very slowly.

Columns with controlled modulus

On the Suez site, the soil consists of a 6 to 7 mthick mediocre layer followed by about 3 m ofcompacted sand and then an alternation of sandand clay layers down to a depth of 30 m.The basic solution selected by EDF consisted of boring 80 cm diameter, 35 m deep piles.Menard Soltraitement then proposed a technicalsolution for the foundation of the two 45 mdiameter, 19m high oil tanks based on the use ofCMC (Controlled Modulus Columns).These CMCs pass through the weak upperlayer and are embedded in the load bearinglayer. A distribution mattress composed of anapproximately 40 cm thick layer of good mate-rial was then placed on these columns, and theunderside of the oil tanks was placed directlyon this layer. Menard Soltraitement deter-mined the optimum grid, depth and diameterof the columns using a Finite Element MethodAnalysis. A total of more than 1 800 CMCswith a diameter of 42 cm and a total length ofabout 15 000 meters were constructed in amonth and a half using a specially designedmachine. The total saving is high consideringthe reduction in the foundation depth andelimination of beams over the pile caps.

ParticipantsClient : EDF International.Contract Manager: EDF CNET.Main Contractor: SAEI/ORASCOM JV.Specialized Contractor: MenardSoltraitement.

Above, the Port-Saïd soil consolidation sitecarried out by the use of prefabricated drainscombined with an overburden consisting of temporary fill.

Menard Soltraitement used the controlled modulus columns (CMC) technique for the Suez site.

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A t the moment, Penang bridge is theonly link between the island ofPenang and the Malaysian peninsula.

It now carries 52000 vehicles per day, which ismuch more than when it was inaugurated in1985, and traffic is still increasing. Thisincrease is due to recent developments inmanufacturing and commercial activity onthe island and in the hinterland. Faced withthis phenomenon, the bridge concession com-pany, the Penang Bridge Sdn Bhd (PBSB),appointed Freyssinet PSC Malaysia to per-form a contract to renovate the bridge staycables on August 9 1999. All the works weredone by Freyssinet PSC (M) Sdn Bhd with theassistance of Freyssinet International in Franceand Freyssinet APTO in Kuala Lumpur.Freyssinet PSC (M) Sdn Bhd worked with theassistance of EEG Simecsol as the consultingengineer and WS Atkins as the independent

inspection organization. All works were per-formed without any interruption to trafficduring the construction period (ten months).

Investigation, design and construction

Due to the lack of any reliable informationabout the condition of the bridge, the firstphase of the works consisted ofinvestigation (coring and measurements ofstress relaxation in the concrete) and design(complex three-dimensional model). Theworks began after the Chinese new year, onFebruary 15 2000, with the preparationphase that consisted of installing temporaryworks access platforms and scaffoldingerected to the top of the four East and Westtowers. The investigation activities showedthat the concrete strength in the deck waslower than expected. A new works programwas then submitted to PBSB in June 2000and was approved by both parties inSeptember 2000. This program includedthe supply and placement of fourpermanent double bearings between theexisting deck and pylon crossbeam, andeight rubber bearings between the deckand the towers acting as a longitudinalrestraint for the deck. It also included theinstallation and tensioning of sixteentemporary stay cables, the removal ofexisting E2 and M2 front and rear staycables, the coring in the deck and thetowers to extract the original stay cable

anchors composed of bars fully injectedwith cement grout. This last operation hasproved to be very tricky due to the lengthand diameter of the cores. The works werecompleted by the placement of twelveFreyssinet stay cables and their associatedcomponents, thus by removal of thetemporary stay cables and finally by theload transfer to the permanent upgradedstructure. All works were completed onDecember 21 2000.

ParticipantsClient and Contract manager: Penang BridgeSdn Bhd (PBSB).Design office: EEG Simecsol.Inspection office: W. S. Atkins.Main contractor: Freyssinet PSC (M) Sdn Bhd.

Penang bridge

Renovation

The stay cables for Penang bridge needed to be partially renovated,since the bridge carries much heavier road traffic than when it wasinaugurated in 1985.


Malaysia

Main volumes> Monolithic reinforced concrete cores

through deck and pylons: diameters 325mm and 470mm, lengthvarying from 4000 mm to 5300mm

> Steel works for temporary stay cable anchorages: 25 t.

> 15.7 mm temporary stay cables: 15 t.> 15.7 mm permanent stay cables

(unbonded strands in galvanized tubes): 23 t.

> Twin bearings permanently couplewith silicone paste, capacity of 2 x 6 000 kN: 4 assemblies.

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France

17

T he Rhone-to-Rhine canal passes acrossFranche-Comté and South Alsace betweenDole and Mulhouse, following the Doubs

for more than 220 km. It was built at the initia-tive of Charles de Saulces de Freycinet, thenPublic Works Minister, in the 19th century, with atotal difference in elevation of 160m and includes41 locks between Mulhouse and Belfort, and75locks from Belfort to the Saône. It was a majortrading route until the middle of the XXth cen-tury, but is now used mainly for tourism.2800 boats used it last year, and many cycliststraveled along its tow tracks forming part ofthe cycle route from Nantes to Budapest. Arestoration program entitled "Future of the areabetween the Saône and Rhine" was decided uponto repair degradation to the canal and its facili-ties. This restoration and improvement opera-tion is scheduled to take place during the period

when the canal is not used for navigation, and inparticular includes mechanization of gates, con-struction of new control stations, plantationsand signs.

Cleaning and stripping

Since the beginning of October, Freyssinet hasbeen working on thirteen locks distributed alongthe length of the canal, including a flat entrylock. The works consist of cleaning lock cham-bers with an average width of 5.2 m and an aver-age depth of 5.5 m, repairing stonework andreplacing gates.The VNF (Voies navigables de France) companyconstructed the cofferdams necessary before lockchambers could be emptied and old woodendoors could be disassembled. In each lock,Freyssinet cleans the stonework by high pressurewater stripping, repoints the stonework andreplaces stones when necessary. New prefabri-cated concrete walls are placed for some cham-bers in which the old side walls have collapsedduring emptying, and some of them are cladwith cut stone.

Mechanization of gates

At the same time, new steel lock gates with a unitweight of 3.6 t are installed with a crane. Onaverage, the Freyssinet teams place four gates in asingle day, and then need 6 days to make alladjustments and do the waterproofing works.These gates are fitted with a remote controlledhydraulic mechanism that will eventually beautomated. Consequently, grooves were con-structed in the lock capping through whichhoses and different equipment can pass. Apart

Locks

Restoration of the Rhine-Rhone canalIt was decided to carry out a restoration program to repair degradation tothe canal between the Rhone and the Rhine built a century and a half ago.

from the lock chambers, Freyssinet is alsorestoring 190 m of stone facing on canalembankments upstream from the town of Dole.To respect the historic importance of this canal,all works done were designed to achieve a glob-al architectural consistency. "A memorable site"commented one of VNF's supervisors.

ParticipantsClient and Contract manager: VNF.Main contractor: Freyssinet France.Co-contractor for the gates: Métalform.

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Spain

18

Renovated churchesFreyssinet is continuing its historic monuments renovation activity and is now working on two very ancient churches.

Restoration of Santa Maria de la Asunción Church

T he Santa Maria de la Asunción parish churchis located in the old district of the town ofAlcala del Rio (near Seville in Andalusia)

and is surrounded by place del Calvario andPadre Ruiz Paez, Padre Aguilar and HermanosMarchante streets. Its bell tower is an example ofreligious art in the Mudéjar period (XIIth to XVIth

century art influenced by Islam) and consequent-ly is architecturally very important.Freyssinet is doing the rehabilitation works forthis historic monument. Foundations inside thechurch are strengthened by a reinforced concreteslab. The 0.60 m load bearing walls, affected bywater infiltration by capillarity, are drained usingthe Electro-Osmosis-Foresis TRABE system.Vertical and horizontal cladding is chipped andthe masonry is rebuilt. The arches consisting of9 cm thick double hollow bricks are reinforcedand marble and ceramic tiles are installed. Thebells are disassembled and cleaned before beingreassembled. The clock mechanism is replacedand metallic reinforcing straps are installedaround the bell tower at two different levels on theoutside (at 15 m and 18 m). Like on the inside,the external masonry is repaired and the externalcladding is made waterproof. Finally, concreteprotections are built for the staircase portal and alightning arrester is installed on the bell tower.

Renovation of Santa Maria La Mayor church in Linares

Santa Maria La Mayor church in the small townof Linares (Jaen) is unique among all buildingsthat have survived Spain's history, as a result ofevents that occurred in the region during thesecond half of the XVIth century. There is aremarkable contrast between the Gothic partwith three naves with five spans each, and theRenaissance part composed of three transepts

with semi-circular arches decorated with cofferson the intrados and terminating in wall ribs.The renovation works done by Freyssinet SAinclude two main packages, firstly underpinningof the foundations, and secondly waterproofingof the transept roof.The works began by improving the ground bybentonite and cement grouting. A drainage sys-tem was then constructed to prevent incomingmoisture and water flows. Freyssinet also made agrout curtain in a crypt, made foundation under-pinning by grouting and installed a siphon.Internal and external cladding were cleaned, andall floor slabs in the monument were repaired.Architraves in the gothic nave and wall buttresseswere reinforced before protecting, polishing andvarnishing the altar.

Historic monuments

>

<

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Pacific Construction Co. Ltd was rewarded for its works on viaducts carrying an expressway in Taiwan.


Taiwan

19

F reyssinet Egypt, which had already workedon the extension of the Suez cement facto-ry between May 1997 and June 1998, is now

participating in the construction of a cement fac-tory close to El Soukhna (Suez). The worksinclude the construction of four 86 m high,20 m diameter raw materials storage silos, witha unit capacity of 16 000 m3; four 78 m high,20 m diameter cement silos with a unit capacityof 20 000 t; and four 64 m high, 16 m diametercement silos with a unit capacity of 10 000 t. Atotal of 5 600 anchors, 800 t of cables and10 650 m of ducts will be constructed.The works started with the construction of two

Construction of cement factory

P acific Construction Co. Ltd received theprize for excellence in ConstructionAutomation for their MSS Mobile

Scaffolidng System used for construction ofC301 viaducts. These structures form part of theconstruction project to build a second express-way in Taiwan and include more than 50 spans.The committee emphasized four importantpoints about the method of construction.Firstly, labor saving. Productivity improved by26.5% due to the high degree of automation ofthe equipment.

Secondly, innovation. The MSS is unique inTaiwan. It uses a single bracket that is selflaunched without the need for a crane.Thirdly, the environment. The superstructureswere built without the need for access fromthe ground, minimizing the impact on theenvironment.Fourthly, technology transfer. Freyssinet carried outthe design work for the Mobile Scaffolding System,and also supervised fabrication, technical assistanceon site and technology transfer for the main con-tractor.

ParticipantsClient: Taiwan Area National ExpreswayEngineering Bureau.Contract manager: Pacific Construction Co. Ltd.Consulting engineer: China EngineeringConsultants Inc.Specialized contractor for design of equipment, construction methods and prestressing: Freyssinet Taiwan Engineering.

Award for ConstructionAutomation

Egypt

New cement factory with large capacity silos is now under construction in the Suez region.

Mobile Scaffolding System

Silos

production lines, and Freyssinet Egypt started athird and fourth production line while the sec-ond line was being terminated. The works start-ed in October 1997 and will be completed by theend of 2001.

ParticipantsClient: the Polysius/Orascom Construction for industries Consortium.Contract manager: Arab Consultant Engineer(ACE).Design office for prestressing: EEG Simecsol.Specialized contractor: Freyssinet Egypt.

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Santa Maria La Mayor Church.Freyssinet SA worked on the complete restoration of this historic monument located in the heart of Linares (Spain).

GB 210/COUV 12/04/01 15:01 Page 1

Footbridge over the Cher N°210 - January - Freyssinet

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