V S L S S I 2 0 0 0 STAY CABLE SYSTEM
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Industrial Ring Road Bangkok, 2008
VSL a worldwide networkFrom concept to site works, the VSL network oflocally operating units adds value throughoutall stages of a project by providing fully-customised solutions, developed andimplemented by highly-trained and experiencedstaff working in close partnership with clients.Customers have access to a local partner,while benefiting from global resources, know-how and expertise as well as VSLs continuingdevelopment of specialist constructiontechniques.
VSL a commitment to quality,safety and sustainable developmentVSL pursues a strong quality, safety andsustainable development policy in keeping withits leading position as a specialist contractor.Proactive management systems have been
VSL - LEADINGIN STAY CABLETECHNOLOGY
established to address local needs whileensuring a high common standard throughoutthe company network.
VSL recognises that its employees are the keyto competitiveness, efficiency and safe workingpractices. The company is committed toSafety First and strives for Zero Accidentby motivating and empowering its employeesto act responsibly in order to achieve these goals.
VSL a specialist stay cable contractorAs leader in stay cable technology, VSL offersthe solutions to tackle todays challenges incable-stayed construction and develops thenext-generation systems in close collaborationwith its clients. The recent boom in cable-stayed bridges with considerably increased
spans and cable lengths calls for fastererection cycles and increases the dynamicdemands on the stay cables. VSLs lightweighterection equipment, compact strand bundlesolutions and its highly-efficient and reliabledamping systems lead the way in meetingtodays needs.
Its vast experience led VSL to launch the SSI 2000 system, which has been installedvery successfully on more than 100 projects inrecent years. VSLs latest developments extendthe SSI 2000 range to provide even greaterflexibility for a multitude of applications, whilemaintaining the systems proven outstandingperformance. VSLs portfolio is now well over150 cable-stayed bridges.
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Uddevalla Bridge Sweden, 1998 First VSL Friction damper
La Unidad Bridge Mexico, 2003Full scope of bridge construction.
New VSL developments in stay cable technologySSI Saddle, a patented design facilitatingsimplified pylon layouts resulting in enhancedbridge aesthetics and increased structuralefficiency
SSI 2000-C, a compact stay cable system withreduced cable diameter and therefore reducedwind drag
SSI 2000-D, a stay cable protected againstcorrosion by dehumidification techniques - apatented solution offering the smallest cablediameters available in strand technology andminimising wind drag while fully maintaining theadvantages of strand-by-strand replacement
A choice of two damping systems to controlcable vibrations efficiently, adapted to thecharacteristics of the structure
Modern engineering tostringent standardsDesigners, owners and authorities aredemanding: Increased long-term performance of stay
cables, tensile members and anchorages;leak-tightness of the anchorage assembly;easy inspection and maintenance; thecapability to replace cables with minimalinterruption to bridge traffic; and reliablecontrol of cable vibrations
Minimal wind drag for long spans Outstanding static and fatigue behaviour,
validated by performance testing Incorporation of damping systems at the time
of installation or as part of dynamic retrofitting Improved aesthetics by using compact
anchorages, saddles and coloured cables
Main contractors seek: Simple interfaces between deck erection and
stay cable installation with a reduced numberof activities on the critical path
Lightweight installation equipment,facilitating a flexible erection schedule thatseparates deck and pylon construction fromthe stay cable erection works and minimisesthe crane time required
Owners benefit from: Enhanced durability Substantial savings on maintenance
The VSL SSI 2000 Stay cable system is designedto meet the requirements and applicablespecifications issued by fib (InternationalFederation for Structural Concrete), PTI (Post-Tensioning Institute) and CIP (CommissionInterministrielle de la Prcontrainte).
Designed to lastVSL Stay cables have a design life of 100 years even in the mostaggressive environments. Elements are fully replaceable withoutrequiring modifications to the structure. All the materials used havebeen carefully selected and all components have been detailed to meetthe highest durability criteria. In addition, the modular nature of the VSL SSI 2000 Stay cable system helps reduce the environmental impactof maintenance operations by minimising the amount of waste generatedwhen parts have to be replaced during the structure s life cycle.
Masang Xi Bridge China, 2001
First application of theVSL SSI 2000 system
CREATING SUSTAINABLESOLUTIONS TOGETHER
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The SSI 2000 wedge anchorages and its tensilemembers as well as its protective system meetthe most stringent requirements for durability,tensile capacity and fatigue performance. Itsstrand-by-strand technology ensures maximumflexibility and full capability for replacement.
High fatigue performanceThe anchorage assembly is designed to controlthe deviation of individual strands and to filtercable vibrations outside the wedge anchoragezone. Its outstanding fatigue performance hasbeen demonstrated in fatigue tests asspecified in the latest recommendations by PTIand fib with imposed angular deviation of the
anchorage from the cable axis. A tension ringor a guide deviator can be used to bundle thestrands at the exit of the guide pipe.
Durability and multi-barrier protectionAll SSI 2000 stay cables are engineered for adesign life of 100 years in the most aggressiveenvironments.The unique feature of individual encapsulationof each strand within the anchorage assemblyeliminates the risk of corrosion migrationbetween strands. The multi-barrier protection system is achieved inthe free length by individually sheathed, greasedor waxed strands with optional galvanization
within the protective outer stay pipe. The protectionis maintained in the anchorage assembly by aflexible gel filler injection, which has passed thestringent leak-tightness tests specified by PTI and fib.
Cable installation with lightweightequipment and minimum impact onother erection activitiesThe compact nature of the anchorages and thestrand-by-strand installation with lightweightequipment frees tower crane time and does notrequire any heavy deck equipment. Therefore,the stay installation does not impair the keyactivities in a typical deck and pylonconstruction cycle.
SSI 2000: VSL STAY CABLE TECHNOLOGY
Individual encapsulationand deviationEach strand is individually protectedwith a multi-layer barrier system insidea leak-tight anchorage assembly andis separately guided to filter bendingstresses at the anchorage entrance
Several complementary barriersFor complete water tightness of the anchorage
Replaceable strand system in a durable stay pipeSheathed, greased or waxed strands withoptional galvanization, protected in anHDPE pipe with proven ageing performance.Each strand can be individually monitored,inspected and replaced
Compact anchorageFully prefabricated including itscorrosion protection in controlled factoryconditions
High fatigue resistance Demonstrated in fatigue tests in accordancewith fib and PTI requirements undercombined tensile and bending action
Anchorage protection capwith flexible gel fillerStrands encapsulated by apolymerised and bonded filler,achieving reliable corrosion protectionwhile allowing access for inspection ifnecessary
The SSI 2000 Stay cable system is based on VSLs proven strand technologies
Adjustable (or fixed end) anchorage
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Cable replacement strand by strandwith minimum traffic disruptionStrands can be individually monitored,inspected and replaced: entire cables can bereplaced strand by strand. The use oflightweight equipment minimises the impacton vehicular traffic and cable replacement canbe achieved under single lane closures.
VSL Dampers The stay cable can be designed with two typesof dampers, the VSL Friction damper or the VSL Gensui damper, or provision can be madefor later installation.
GYAnti-vandalism protectionDesigned to protect the stay cable abovedeck level and to accommodate an optionaldamping system
Low drag coefficient andaeroelastic stabilityExternal helical ribs tested in wind tunnel forefficient control of rain-wind inducedvibrations. Two options for even lower winddrag SSI 2000-C and SSI 2000-D with reduced stay pipe diameters
Free tension ringLocated inside the stay pipe. Can be replacedby a guide deviator, depending on thegeometry at the exit of the guide pipe
SSI Saddle with fully replaceable strands For extradosed bridges and cable-stayed bridgeswith compact pylon arrangements, VSL offers apatented saddle solution compatible with the SSI 2000 system. The compact saddle designallows for strand-by-strand installation andreplacement and achieves a safe and reliableanchorage for unbalanced