VSL NEWSISSUE TWO 1993

Editorial

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A t last year's VSL Symposium in Montreux we unveiled our new VSL post-tensioning system. Today, wecanreport the first successful applications. For instance in Denver, Colorado, a fifteen million litre tank hasbeenbuilt using both, the new VSL CS Anchorages and the VSL PT-PLUS Plastic Ducts. The front cover showswhat a clean and workmanlike result can be achieved with the new system. Say good bye to do-it-yourself tapecouplers and no unprofessionally fixed grouting tubes. The anchorages are highly practical and easy to install.On page 10 you can read more about The Denver Tank.

The development of the VSL COMPOSITE SYSTEM was very much in the hands of Dave Rogowsky. Duringthe crucial period of the process of developing the system Dave was located at our headquarters, injectingideas and coordinating efforts. We are very honoured to announce that - alter Prof. Dr. Peter Marti - anotherVSL staff member has been appointed to an academic position. Dave has started his new assignment as atenured Professor with the University of Alberta in Edmonton, Canada, on August 16, 1993.

The outstanding careers of Peter Marti and Dave Rogowsky clearly demonstrate that VSL is more than just ahard-ware supplier in the field of post-tensioning.We are specialist contractors providing optimized design and construction solutions to construction industrycustomers. Our engineers are eager to find technically sound answers to any construction problem. Togetherwith our field staff, they establish hands-on and economical methods. Our aim is to provide solutions whichbring optimum financial benefits to you, our clients. We know that we will only continue to prosper as long asour customers are satisfied with our products and services. If you need practical ideas combined withoutstanding performance, call VSL !

The VSL Composite System Has Taken Off

Dave Rogowsky

Reto jenatschGroup Chief Executive Officer

Cover :

What looks at the first

glance like routine work is

one of the first applications

of The VSL Composite

System combined with

PT-PLUS duels at

The Denver Tank

Highlights of this Issue :

3 Innovation in Rehabilitation / Haller Award

6 The Mekong River Bridge Project

9 Tsing Ma Bridge Hong Kong

10 First Use of VSL CS Anchorge

13 Troll Gas (GBS) Norway

Innovation in Rehabilitation

The Bell at the Holy Cross Church Now Rings

An innovative method of retrofitting masonrystructures makes its debut in the UnitedStates in the brick walls of the 104-year old HolyCross Church located in Santa Cruz, California.Severe structural damage, inflicted during the1989 Loma Prieta earthquake, dosed thechurch. Removal of the bell tower steepletestified to the severity of the damage.

Shortly alter the closing of the church, VSLCorporation began developing retrofit conceptsto non only restore the structural integrity of thechurch, but also to fortify the church to resist theseismic forces of tomorrow. Refined structuralanalysis and material testing culminated in adefinitive retrofit plan.

VSL designed and installed an in-plane rooftruss to provide lateral stability to thebuttresses, and at the same lime transfer acontrolled amount of shear to the end walls andbell tower ; thereby enabling an accurateassessment and design for the shear acting onthe walls.

VSL conduded its work by crowning the belltower with a reconstructed steeple. The churchreopened and now the ringing of the belltestifies to the new life that VSL can install intomagnificent old structures.

On June 8, 1993, the Masonry Society haspresented the first Haller Award to VSLCorporation for the HolyCross Churchretrofit. The award honours the “creative useof structural masonry”. It is named after thelate Swiss Professor Haller.

Holy Cross Church and lifting of steeple onOctober 17, 1992

First, VSL grouted the cracks inthe masonry; then vertically

cored one hole down each ofthe eight buttresses on be:

sides of the church to receivea VSL 5-12 tendon which

stabilizes the wall and fixesthe buttress to the

underlying foundation. In a similar fashion theback wall of the churchand the bell tower at thefront of the church each

received four VSL5-7tendons

Convertying Research into Reality

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Electrically lsolated Tendons for Anchors

V SL has since 1985 been providing inSwitzerland ground anchors that wereelectrically tested. Such testing canbeconducted prior to transportation and atsome stages of installation. These testspositively checked the integrity of theencapsulation of the bond and free lengthprior to stressing. There was however noestablished method to similarly check theelectrical isolation and hence the completeencapsulation alter final stressing andduring the design life of the anchor. Thisdoes non mean that corrosion will be afuture problem but it does mean that theseanchors lacked a Quality Control methodthat would conveniently provide assuranceof adequate remaining life.

Combined with the development of VSL'S CS-Super configuration (see VSL NEWSnumber one 1993) the concept of completeelectrical isolation was studied andintroduced. It is obvious that if the steelelements are totally isolated from waterand air throughout the design life thenadequate protection against corrosionexists.

Rock anchors : For rock anchors aprocess to extend the free length plasticduel to contain the anchor head, whileallowing for standard stressing andinspection access, was developed. Theanchor head encapsulation must cope withthe high contact forces between bearingplate and anchor head and also provide forrepeated access for inspection, forceadjustment and the installation of forcemeasuring load cells. The first use ofcompletely Electrically Isolated Tendons(EIT) rock anchors was on the upgradingof the slope stabilisation for the northernportal of the Seelisberg road tunnel inSwitzerland. This EIT anchor project wascompleted in 1992. It included 100 anchorswith an ultimate capacity of 3350 kN andlengths up to 44 m.

Soil Anchors : The development workhere had to be mindful of the soil drillingprocess. A connection technique betweenthe free length duel and the load bearingisolation that was electrically tight andwhich could also provide the same type ofaccess, as mentioned for rock anchors,

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evolved. The first use of this type of EITsoil anchor was for the stabilisation of arailway curling at Dreispitz in Basel,Switzerland. In ail, 47 EIT soil anchorswith an ultimate capacity of 1110 kN andlengths up to 30 m were installed duringspring 1993.

Both types of anchors were successfullyelectrically tested while being subjected totheir rated load capacity. The performanceof the seals between component partswere tested by measuring the electricalresistance between the water filled innervoid of the test anchor and the water filledouter surround.

The application of EIT techniques toground anchors allows the use of effraientquality control methods to assure ownersthat their anchors still possess completecorrosion protection throughout theirdesign life.

Brad RathboneVSL International Ltd.Berne, Switzerland

Seelisberg tunnel

South East Asia/Australia

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The Mekong River Bridge Project

The first bridge to cross the lower MekongRiver is currently being built betweenThailand and Laos near Vientiane, the Laotiancapital. The bridge is a girl to Thailand and Laosfrom the Australian Government and wasdesigned by Maunsell Pty. Ltd. and SinclairKnight Pty. Ltd. The successful constructiontenderer was John Holland Constructions Pty. Ltd.

VSL'S scope is the supply and installation ofpost-tensioning, and segment erection. Themain structure has an overall length of 665 mconsisting of five 105 m internal spans and two70 m end spans. The deck is a 12.7 m widesingle cell box girder with a variable depthranging from 6.1 m at the piers to 2.6 m at themid-span of the infernal spans, and 2.1 m at thetransition with the approach structures. Thebalanced cantilever construction uses matchcast epoxy jointed segments weighing up to 73tons. Individual segments are temporarilysupported by five longitudinal VSL CTstressbars.

The approach structures have overall lengths of269 m and 240 m with maximum spans of 36 m.The deck is a 12.7m

wide single cell box girder with a constant depthof 2.1 m for compatibility with the end spans ofthe main bridge. Longitudinal post-tensioning ofall girders consists of a combination of 5-19tendons and 38 mm diameter VSL CTAstressbars.

David PashVSL Prestressing (Aust.) Pty. Ltd.Noble Park, VIC, Australia

Balanced cantiever construction at MekongRiver Bridge

Sudirman Flyover

L ocated in the busiest and most importantstreet of Jakarta Jalan Sudirman, VSLIndonesia was awarded the subcontract work toconstruct the superstructure of this firstincrementally launched bridge in Indonesia. Theaward came alter VSL submitted an alternativedesign to the Main Contractor PT Wijaya Karyaand the City Authority, saving time and money and

Overall bridge with casting

yard in the background,

and Jaunching nose

position before reaching

the pier, spanning the main

street of Sudirman

The Modular Tower System, quality fabricatedfrom in excess of 600 tons of structural steel,has the capacity to tilt loads up to 2000 tons.However, being modular, various combinationsof system are possible, ranging from a twotower system stabilized by guy wires to a 4tower system without the need for additionalstability. Precast concrete foundations alsofabricated in modular form further enhanced thetower system stability.

The tower modules, each 10.5 meters long andweighing 10.5 tons, were rapidly erected andpinned together. Standardlifting beams and

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911 tonson the way up

T he heavy vessel installation contract atMobil Oil Singapore CCP and AromaticsExpansion Project included 6 vessels ranging inlength from 9 m to 95.3 m and varying in weightfrom 50 tons to 911 tons.

The S$ 600 million plant at Jurong set a worldrecord with the installation of the largest xylenesplitter fractionating column ever built. This isthe largest of the 36 vessels erected by VSLSingapore Pte. Ltd., 5 of which utilized the VSLModular Tower System for installation.

Mobil Oil Singapore Pte. Ltd., CCR/Aromatics Expansion

preassembled bracing was normally erected bycrane, with only the 32 meter long, 80 ton headtrusses being lifted into position using SLU-70heavy lifting jacks. For the xylene splitter towertilt, four SLU-330 ton jacks were positioned onsliding 'C' frames slung under the trusses. Thisallowed the tait vessel to be lifted through thetowers and then slid horizontally into positionover its foundations. VSL'S contract includedfuit responsibility for lifting all 36 vessels.

John DavieVSL Singapore Pte. Ltd.Singapore

avoiding disruption to traffic as compared to theconforming in-situ bridge design.

Work started in October 1992 with the castingyard. By fate December 1992 the first segmentwas cast. Segment lengths are typically 14.5meters with end segments of 12 meters. A total

of 12 segments for this 165 m long 30° skewbridge, with a slope of 5 %, were needed.

The bridge consists of two single box girders.Launching is carried out with two ZPE 200jacks. Span lengths are 31-3337-33-31 meters.A safety system with emergency push button

operation was provided. Construction cyclesclown to seven days were achieved withoutsteam curing.

Johannes Himawan PTVSL IndonesiaJakarta Indonesia

North East Asia

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VSL Group Efion a Major Force in New Taxiway Bridge for Hong KongVSL Japan

delivers Quality Training for QualityPerformance

The VSL network in Japan has grownextensively in recent times. Mindful ofthis growth and understanding therewards of well trained personnel anintensive training workshop for 200attendants was conducted to providefuture operators, planners andconstruction managers with the neededknow how.

The workshop dealt with thefamiliarisation of VSL constructionmethods, the operation for conventionalpost-tensioning and ground anchors.Precise operations and maintenanceprocédures for post-tensioning equipmentfrom single strand jacks to 1500 t capacityjacks were demonstrated.

The Japanese construction industry willbe well served by this capable team.

Shusuke SakataVSL Japan CorporationTokyo, Japan

As part of measures to cope with a rapidincrease in Hong Kong airport's trafficmovements a new aircraft Taxiway bridgeconnecting the existing runway and newapron parking bays was required. On this 13month fast track contract, VSL Hong Kong inconjunction with VSL Redland ConcreteProducts played a major role.

VSL Hong Kong were contracted by the maincontractor Dragages et Travaux Publics tocarry out the design and documentation ofthe bridge superstructure, transportation andplacement of the precast beams and thedesign and installation of the bearings andjoints. VSL Redland were responsible forcasting the 154 Post-tensioned T-beams attheir « Little Montana Island» casting yard, inthe People's Republic of China. This contractwas the first Civil Engineering contract inHong Kong to employ ISO 9000 qualitystandards.

The new bridge a 220 m long seven spanstructure was conceived using a maximumspan of 36 m. The structure comprised of1380 mm deep precast post-tensioned wideRange T-beams with a 220 mm thickconcrete topping.

Precast T-beams proved to

be the most cost-effective

solution for this bridge

The beams were transported to Hong KongHarbour by barge. Due to airport heightrestrictions, the installation procedure wascomplex requiring most work to be carriedout at night.

To satisfy the loads from a Boeing 747400and 175 mm movements at the joints,purpose designed 40 mm plate finger jointswere employed. The bridge was supportedon 207 large elastomeric bearings andemployed auxiliary restraint devices to resistearthquake and aircraft breaking loads.

This project with its tight programme anddemanding quality requirements has onceagain shown the VSL Group's reliability,strength and diversity in the technical andconstruction fields.

Trevor GregoryVSL Redland Concrete Ltd.Hong Kong

Barry YoungVSL Hong Kong Ltd.Hong Kong

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Work is well under way for theconstruction of the 2.1 kilometer TsingMa suspension Bridge which will form one ofthe major links between the new Chek LapKok Airport and Hong Kong.

In August 1992 VSL was awarded thesubcontract to construct the main concretetowers, eight approach piers and to post-tension the mass concrete suspension cableanchorages. all works being of a highlytechnical nature. For this work the VSLGroup support worldwide has been calledupon to provide the needed technical andconstruction experience.

VSL'S experience in continuous slipformingis essential for the construction of the 206 mhigh concrete towers. At a rate of 3 m per daythe complex shaped towers with complicatedreinforcement layout will be completed within3 months. To provide temporary stability tothe towers, eight steel trusses weighing up to160 tons shall be lifted into position by theVSL Heavy

Lifting System and then stressed onto thetowers. The eight approach piers will beconstructed by the VSL climbform method.To meet the fast construction program fourVSL climbforms have been mobilized toensure the completion of each 60 m high pierwithin 80 days.

To restrain the suspension cables 520 tonsof post-tensioning shall be placed in the twomass concrete anchorages. The 388tendons of each anchorage comprise 30individually greased and sheathed tendonsplaced in a mita steel pipe duct with aspecially modified anchorage for connectionof the suspension cables.

Barry YoungVSL Hong Kong Ltd.Hong Kong

The fast growing Tsing Yi Tower at a height of

150 m with one of the piers in the foreground

Tsing Ma Bridge Swings into Full Gear

USA

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The First Use of VSL CS Anchorages

Construction is currently underway inDenver, Colorado, on a four million gallontank, the first project to use the new VSLComposite System and PT-PLUS Plastic Duct.The system was chosen be cause it providesthe maximum corrosion protection availablewithin the post-tensioning industry.

The CS 5-12 and 2 3/8 " (59 mm) diameter PT-PLUS Plastic Duct are used in the ring beamfooting, and horizontally within the tank wall.

We are using our SO 6-4 and flan PT-PLUSPlastic Duct vertically in the walls to providesuperior post-tensioning protection. The fullyencapsulated VSL CP+ System is beingused for the ground and roof slabs ; theconcrete in these members will be poured inone monolithical pour.

VSL provided post-tensioning materials,labour and rebar labour. VSL also designedthe post-tensioning system

to meet the requirements of the structuraldesign. And, VSL worked closely with thecontractor to develop a compressedschedule which took six weeks off thecompletion date. The tank diameter is 200 ft(60.96 mi with a 19 ft (5.79 m) high cast inplace wall.

Robert H. AllenVSL CorporationLakewood, Colorado

Mynle Beach Convention Center SuperTruss TM

Front view of the Denver Tank

The City of Myrtle Beach, South Carolina,selected a fast track design/build methodfor the construction of their new $20,000,000Convention Center. The winning team ofCentex-Rooney (General Contractor), Bliss& Nyitray (Engineer), and Cannon (Architect)consulted with VSL during the bidding phaseregarding the feasibility of post-tensioningtwo composite steel SuperTrussesTM

spanning 240 ft which provided a100,800sq.ft. (9300sq. m) column-free exhibit space.

Upon the award of the project, VSL wasissued a contract to design, provide, andinstall the post-tensioning system in theSuperTrusses TM .

The SuperTrussesTM combine the use oftwo post-tensioned tendons, 5-15 strandseach as the bottom tension cord, with highstrength concrete (10,000 psi/69mPa)encased by a 20" diameter pipe as the topcompression cord.

The post-tensioning tendons were to bestressed in stages to a final jacking force of 450kips (2000 kN).

The flexibility provided by post-tensioningwas clearly evident when it was determinedthat additional air handling units were neededalter the fabrication and erection of thetrusses. The load of the additional units waseasily accommodated by simply increasingthe final jacking force from 450 kips (2000 kN) to

Keith W. JacobsonVSL Corporation Minneapolis,Minnesota

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490 kips (2180 kN) ; taking advantage of thereserve capacity provided by the post-tensioning tendons.

Robert W. SwardVSL CorporationNorcross, Georgia

Bottom tension chords reflected up for stressing

VSL Provides Solutions for Intermediate Slabs in Malt House Silo

VSL Corporation is nearing completion ofa contract for the design, material supplyand installation, and lifting eight floors withina 290 foot (88 m) tall, 80 foot (24 m) diametermalting silo for the RAHR MALTINGCOMPANY in Shakopee, Minnesota.

The original contract documents were basedon mildly reinforced concrete vola slabs, castin place on formwork. VSL Corporationproposed solid, post-tensioned concretefloors cast at grade and lifted into position.The VSL alternative provided quick,economical construction and yielded asmooth finish on the underside of the floorsas required by the owner.This solution also eliminated the slow anddifficult movement of formwork betweenlevels through the small, exterior siloopenings. The floors, which weigh as muchas 1125 tons, span the silo withoutintermediate supports and are designed tocarry live loads up to 600 psf (28 kPa).

Using VSL Heavy Lifting, the floors were lifted toheights ranging from 35 feet (11 m) to 270 feet(82 m) and were permanently fixed in placeusing a closure strip around the perimeter of thesilo.

Post-tensioned floor prier to pouring and lifting

Europe / Middle East

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EVRIPOS Bridge nears Completion

In December 1986, we reported in the VSLNews Letter that VSL had been awardedthe contract for supply of stay cables for theEvripos bridge in Greece, with completionexpected by the end of 1988. Due to anumber of delays, work on the stay cablesdid, however, not begin until 1991.installation of the stay cables was completedtowards the end of 1992 and completion ofgrouting is planned for early summer 1993,to be followed by the wrapping of cables withwhite Tedlar tape.

The Evripos bridge carries a two-lane roadbetween the Greek mainland and the blandof Evia. The bridge deck - a prestressedconcrete slab just 450 mm thick – is

carried by 144 VSL stay cables, ranging insize from 6-7 to 6-20, fanning out in twoplanes from the tops of two pylons. Thecables are composed of bundles of 0.6"strands encased by an outer sheath ofHDPE, which is subsequently injected with acement-based grout. When grouting workhas been completed, the cables will becleaned and then wrapped with white Tedlartape, which will improve the appearance ofthe bridge while also reducing thetemperature variations in the cables.The main contractor for the project is a jointventure formed by the Athens-basedcompanies TEV S. A. and HellenicTechnodomiki S.A. The consulting engineeris Domi S.A., Athens.

VSL (Switzerland) Ltd. supplied the staycable components and provided technicalassistance and equipment. The post-tensioning for the bridge deck was suppliedby VSL Systems S.A., Athens. With its mainspan of 215 m and its pylons rising to aheight of almost Q0 m above sea-level, theEvripos bridge, in addition to providing much-needed relief of traffic congestion in thenearby town of Chalkis, will become thedistinctive feature of this picturesque area.

Philip WallaceVSL(Switzerland) Ltd.Lyssach, Switzerland

A view of the bridge following cable installation. Detail : The exposed deck anchorages

TROLL (GBS)Biggest in the World

VSL Heavy Lifting Exchange Steam Generators at Nucelar Power Station

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TROLL (GBS) - the biggest platform in the world,now under construction

Exchange of steam generator

The gravity base structure (GBS) for theTroll Gas Field in the Noah Sea has nowbeen under construction by NorwegianContractors A7S for two years.

The giant GBS will be 369.4 meters high.The completed platform, including topside,will be towed to the over 300 meter deep ;XXX field in July 1995. From there it willextract gas from the biggest sub-sea gasfield in the world serving Europe with Gas forseveral decades. The design operating lifefor the structure is 70 years.

Norske Shell A/S, as operator for the TrollPhase 1 development project have anengineering, procurement and constructioncontract with Norwegian Contractors A/S.VSL Norge A/S has a full service post-tensioning subcontract with NorwegianContractors A7S. In ail, approximately 9'000tons of VSL Post-Tensioning Systems,installed by VSL Norge A/S, will be at work inthe structure.

Kalle NilssonVSL Norge A/SStavanger, Norway

The Beznau Nudear Power Plant innortheastern Switzerland wascommissioned at the end of 1969. Thedecision to replace the two steam generatorsof Unit 1 was essential for assuring thereliability and economy of future operationsat the plant.

The exchange was a complex undertaking,as neither the overhead polar crane at thefacility, nor the access locks, were designedfor handling a complete steam generator.

The consortium of Siemens (Germany) andSulzer (Switzerland) entrusted the transportof the new steam generators into thecontainment area, and the handling thereinto VSL.

Special lifting and transport equipment, alongwith a temporary opening in the containmentwall, enabled the exchange of the massivesteam generators. all vertical and horizontalmovements were carried out using the VSLStrand Lifting System.

VSL'S scope of services on the projectincluded detail planning of movements,design, supply, erection and dismantling of

temporary steel structures such as slidingtracks with carriages, a temporary support toreinforce the polar crane and a temporaryportal on the crane.

The actual exchange work took place inApril/May 1993. Working under a tightschedule and tight conditions, VSLcompleted work on the project ahead ofschedule.

Ferdi Trenkler VSL (Switzerland) Ltd.Lyssach, Switzerland

Western Europe

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Strengthening the Viaduct Oleron

The 2,862 m viaduct links Oleron Islandwith the mainland of France. Thesuperstructure of the bridge consists of aprestressed single-cell box girderconstructed roughly 30 years ago using 3.30 m precast segments. The viaduct isseparated by eight expansion joints into 9sections roughly 320 m long. The mainspans are 79 m long. After a recent structuralevaluation it was decided to strengthen thebox girder.

VSL France has been commissioned for thiswork based on the merit of a VSL alternativesolution. VSL is fully responsible forfurnishing, installing, stressing and groutingthe external post-tensioning system,including all ancillary concrete work relatedto anchoring and deflecting the tendons, inall Q bridge segments.

The external post-tensioning system for thestrengthening consists of a VSL 6-35 tendon,with an anchorage force of 7000 kN,attached longitudinally inside the box girderalong each web. The tendons, roughly 300mlong, are anchored near the expansion jointsinto added concrete diaphragms which arefixed to the bottom slab and each girder web with prestressed bars. The tendons aredeviated at the piers and at midspan of eachspan. VSL'S External Post-Tensioning

System is ideal for strengthening structuresof all kinds, offering many advantages : thesystem provides great capacity with virtuallyno increase in structure weight ; fireprotection and corrosion protection are easilyattained ; the tendons are accessible forvisual inspection and monitoring ; and, when

necessary, the system can be readilyreplaced.

Pierre Bron VSL France S.a.r.lEgly, France

Rebuilding Stade Charlety

The new Stade Charlety Arena, underconstruction in Paris, will serve as a firstclass 20,000 seat sports arena complex anda l400 seat mufti-purpose room completewith offices and underground parking.

Post-tensioned precast concrete frames arethe primary structural elements supportingthe 20,000 seat arena. The concrete framesprovide lateral stability to the arena, andcarry the gravity loads

Charlety during erection of precast frames andstands from the concrete stands

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The world renowned Leaning Tower ofPisa in Italy has been strengthened byPreco S.r.l. of Milano, VSL'S licensee in Italy.The strengthening, in accordance with thetemporary interventions decided by aninternational committee for safeguarding thetower (Comitato Internazionale diConsulenza per la Salvaguardia della Torredi Pisa), utilizes 18 VSL Hoop Tendonsaround the exterior of the tower to preventbuckling of the tower's marble cladding.

The International Committee stipulated thatthe circumferential tendons be non-destructive and non-deteriorating, allowincremental tendon loading and unloading,provide precise force monitoring duringstressing, permit future adjustments andforce monitoring, and have minimal impacton the appearance of the tower. To eliminatethe possibility of XXX the marble, lubricatingcompounds on ire tendons, for inhibitingcorrosion and reducing friction, wereprohibited.

Responding to the challenge, VSLInternational Ltd. devised an optimumsolution verifying the system on a full-scaletest installation on an existing, round,concrete, water tank prior to performing thework on the monument itself. The jackingforce on the tendon was monitored andverified by a load cell, a hydraulic pressuregauge, and measured tendon elongation.

The system uses a galvanized o.6”monostrand, housed in a polymere PVDFduct, and anchored by a Rush-mountedcenter stressing anchorage block (90 x 70 x500 mm) which bears on a tendon slidingpart to protect the marble. Encapsulation ofthe galvanized anchorage block, along with

conjunction with two VSL 6-4 strand tendons.4 to 5 m short tendons are used for fixing inplace the steel tie-clown plates for the long-span steel roof trusses atop the upperframes.

VSL'S reliable involvement on the project,from pre-tender consulting through finalinstallation and stressing, is a significant

a significant contribution to the timelyconstruction and long-term integrity of thenew Stade Charlety Arena Complex.

Pierre Bron VSL France S.a.r.lEgly, France

from the concrete stands and the eight long-span steel roof trusses.

VSL'S work on the project includes post-tensioning the 52 frames on the level of thelower stands using four VSL 5-7 strandtendons per frame, and post-tensioning the16 frames on the level of the upper standsusing six VSL 6-7 strand tendons in

surface treatment of the wedges, / assureslong-term corrosion protection for thesystem.

The «extraordinary» care exercised byVSL/Preco in the design, testing andinstallation of the circumferential prestressing

for strengthening the Leaning Tower of Pisaassures that the Monument will remain“extraordinary”.

Alberto LodigianiPreco S.r.l.Milano, Italy

Circumferentialprestressing single strandanchorage body

Prestressing the Leaning Tower of Pisa

AUSTRALIAVSL Prestressing (Aust.) Pty. Ltd. VIRGINIA OLDTel 61 - 7 -285 64 00Fax 61-7-2667534

VSL Prestressing (Aust.) Pty. Ltd. NOBLE PARK, VICTo 61-3-7960.366Fax 61 -3 -795 05 47

BRUNEI DARUSSALAMVSL SYSTEMS(B)SDN BhdBANDAR SERI BEGAWANTel 673 -2- 22 91 53,-22 18 27FAX 673 -2- 22 19 54

HONG KONG VSL Hong Kong Ltd Quarry Bay, HONG KONG Tel 852 - 590 22 88Fax 852 - 590 02 90

VSL Redland Conor. Prod LtdQuarry Bay HONG KONG Tel 852 - 590 03 28 Fax 852 - 562 94 28

VSL Corporation ATLANTA, GATel 1 -404-446-3000 Fax 1 -404-242.7493

VSL Corporation DALLAS, TX Tel 1 -214-647-0200 Fax 1 -214-641 -1192

VSL Corporation DENVER, CO Tel 1 -303-239-6655 Fax 1 -303-239-6623

VSL Corporation HONOLULU HI Tel 1 -008-682-2011 Fax 1 -808-682-2814

GERMANYVSL Vorspannteahnlk (D) GmbHELSTALTel 49-' 72-510 65 16

GREECEVSL Systems S A. ATHENSTel 30-1 -363 84 53Fax 30-1 -360 95 43

SPAINVSL Iberica SA MADRIDTel 34-1-5561818Fax 34-1 -597 27 01

BRAZILRudloff-VSLIndustmal LtdaSAO PAULOTel 55-11 -026 0.155Fax 56-11 -826 62 66

CHILESistemas Especiales deConsiruaclon SA, SANTIAGOTel 56-2-233 10 57Fax 56-2-231 12 05

NORWAYVSL Norge AS, STAVANGERTel 47-4-563701Fax 47-4-562721

PORTUGALVSL Prequipe SA, LISBOATel 351 1 - 793 86 30Fa.351-1-7930901

GREAT BRITAINBalvac Whitley Moran LtdDERBYSHIRE DE55 4PYTel 44- 773 5416 00Fax 44 - 773 54 17 00

INDIAKillick Prestressing Ltd., BOMBAYTel 91 -22-578 44 81Fax 91 -22-578 47 19

NETHERLANDSCivielco B V. AT LEIDENTel 31 -71 -76 89 00Faz 31 -71 -72 08 86

VSL OFFICE PRAGUEVaolavské namesti 66110 00 PRAHA 1Tel 42 -2 - 236 69 92 Fax 12- 2 -236 73 59

ITALYPRECO S.r I., MILANO Tel 39-2- 481 80 31 Fax 39-2- 481 64 15

PERUPrat ensado VSL ad Peru SA, LIMATel 51 -14-76 04 23,-76 04 26Fax 51 -14-76 04 77

SOUTH AFRICASteeledele Systenls(Pty.) Ltd.JOHANNESBURGTel 27-17-613 7741 /9Fax 27-11-613 74 04

SWEDENIntemordlsk Spannarnlerlng ABDANDERYDTel 46 - 8 - 753 02 50 Fax 46-8-753 49 73

JAPAN VSL Japan Corporation TOKYO Tel 81 -33-346 89 13 Fax 81-33-345 91 53

KOREAVSL Korea C. Ltd., SEOULTel 32 -2 -574 82 00 Fax 82 - 2 -577 00 98

VSL Corporation VSL Corporation LOS ANGELES. CATel 1 -818-358-9864 Fax 1 -818-359-6504

VSL Corporation MIAMI, FLTel 1 -305-592-5D75 Fax 1 -305-592-5629

VSL Corporation MINNEAPOLIS, MNTel 1 -612-456-0986 Fax 1 -612-456-9281

VSL CorporationMonostrand EXPRESS Tel - 800- MONO VSLFax -800-866-6855

TAIWAN VSL Systems Taiwan) Ltd, TAIPEI Tel 886-2- 707 72 53Fax 886-2 -704 04 63

VSL Corporation PHILADELPHIA, PATel 1 - 215 - 750 - 6609 Fax 1 -215 - 757-0381

VSL Corporation SAN JOSE, CATel 1-408-866-5000 Fax 1 -408-379-6206

VSL Corporation SEATTLE. WATel 1 -206-771 -3088 Fax 1-206.672-3020

VSL Corporation WASHINGTON, DCTel 1 - 703-451 -4300 Fax 1 - 703-451 -0862

GUAMVSL Prestressing (Guam), TUMONTel 67 -1 - 646 80 61Fax 67 -1 -649 08 50

INDONESIAPT VSL indonesia JAKARTATel 62-21 -570 07 80Fax 62-21 -5731217

MALAYSIAVSL Engineers (M) Sdn. Bhd.KUALA LUMPURTel 60 -3 -2424711Fax 60-3 - 2429397

NEW ZEALANDPrecision Precasting (Wgtn.) LtdOTAKITel 64-094 81 28Fax 64-094 83 44

SINGAPOREVSL Singapore Pte Ltd SINGAPORETel 65- 235 70 77/9Fax 65- 733 86 42

THAILANDVSL (Thaïland) Co Ltd, BANGKOKTel 68-2237 32 80/89/90Fax 66-2-238 24 48

PUBLISHED BY VSLInternationalLtd.,PO.Box 208 CH-3000 Berne 21/ Swizerland,Tel 41-31-370 62 22, Fax 41-31-370 62 50Editor Theresa Wenger

ADRESSES OF VSL LICENSEES

SOUTH EAST ASIA/AUSTRALIA

AUSTRALIAVSL Prestressing (Aust.) Pty. Ltd. 6 Pioneer AvenueTHORNLEIGH, NSW 2120Tel 61 - 2 - 484 59 44Fax 61 - 2 - 875 38 94

NORTH EAST ASIA

HONG KONGVSL North East AsiaRegional Office1508 Devon House979 King s RoadQuarry Bay, HONG KONGTel 852-590 22 22Fax 852-590 90 93

USAVSL CorporationCorporate Office1671 AvenueCAMPBELL, CA 95008Tel 1 -408-866-67 77Fax 1-408-374-41 13

EASTERN EUROPESWITZERLANDVSL (Switzerland) LtdBernstrasse 93421LYSSACHTel 41 -34 -47 99 11Fax 41 -34 -45 43 22

WESTERN EUROPEFRANCEVSL France s a r I10 Avenue Verdun91520 EGLYTel 33 - 1 -69 26 14 00Fax 33 - 1 -80 83 89 95

LICENSEESAUSTRIASonderbau GesmbH, WIENTel 43 - 222 - 892 02 80Fax 43 - 222 - 892 02 80 33

BOLIVIAPresstressed VSL ofBolivia Jauregui Ltd., LA PAZTel 591 -2-321 874Fax 591 -2-371 493