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  • 8/7/2019 bridge pics


    A record concrete box girder span overthe Kanawha River will soon completethe widening of a 4.3-mile section ofI-64 located in Kanawha County, WestVirginia. T. Y. Lin Internationals bridgedesigners, working with the WestVirginia Department of Transportation,Division of Highways (WVDOH), wereconfronted with the challenge ofcreating a low-cost, durable, andaesthetically pleasing structure thatwould alleviate traffic congestion forcommuters in the Charleston area.The resulting eight-span segmentalbridge design is the first long-spansegmental box girder structure built bythe balanced cantilever method in WestVirginia.

    profile Kanawha RiveR BRidge / Kanawha County, west VirginiaEnginEEr: t.y. L il, ald, V.

    gEotEchnical EnginEEr: td e ic., s. alb, w. V.

    PrimE contractor: Bm Cc Cp, sb, P.

    construction EnginEErs: Fl e gp ic., tll, Fl., d Mcl Bk Cp,

    Cl, w. V.

    concrEtE suPPliEr: a Cc, wfld, w. V.

    Formwork suPPliEr: DoKa, usa Ld., Blm, Md.

    AwArds: 2007 West Virginia Division of Highways Engineering Excellence Award in the Large Bridge Category

    The existing I-64 bridge over theKanawha River between Dunbar andSouth Charleston is a steel plate girderstructure with a 440-ft-long main spanthat was completed in 1974 to carryfour lanes of traffic. The preliminarydesign studies evaluated severalalternatives for increasing the capacityof the existing Kanawha River Bridge tosix lanes, including widening the existingbridge, complete bridge replacement,and construction of a new eastboundbridge. The alternative selected wasthe construction of a new eastboundstructure on an improved nonparallelalignment carrying three travel lanes andone auxiliary lane. The existing bridgewill be modified to maintain four lanesof westbound traffic.

    by Santiago Rodriguez, T.Y. Lin International



    The Kanawha River Bridge shown in this rendering

    has the record span in the United States for a

    concrete box girder at 760 ft. All photos and

    renderings: T.Y. Lin International.

    a 760-ft-lo

    m sp s t lost

    cocrt box rr sp

    t Ut Stts.

    30| asPire, w 2009

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    Cast-in-PLaCe segMentaL Box girDer BriDge / west Virginia DePartMent oF transPortation, ownerBridgE dEscriPtion: 2975-f-l b d bd

    structural comPonEnts: 66-f-d l-cll b d p fm 144 760 f bl b blcd clv.

    Fv l f ppc p d -lld m p p. Dlld f fd.

    Form travElErs: struKturas, Ld, n

    BEarings: r. J. w ic., am, n.y.

    ExPansion Joints: w Bm acm Cp, am, n.y.

    Post-tEnsioning: VsL, Dll, t.

    grouts: BasF, skp, M.

    BridgE construction cost: $75 Mll ($379/f2)

    The bridge types evaluated for thenew eastbound structure included asegmental concrete box girder, steeltied arch, steel box girder, concretecable-stayed bridge, and a steel truss.The segmental concrete box girder

    and steel arch alternatives wereselected for the type, size, and locationstudy. After evaluating constructioncosts, maintenance requirements,and constructability, final plans weredeveloped for a segmental concrete boxgirder bridge.

    Be lyWith a total length of 2975 ft, theKanawha River Bridge will span arailroad track operated by NorfolkSouthern, Dunbar Avenue, the Kanawha

    River back channel, Wilson Island, theKanawha River main channel, RiversideDrive, and MacCorkle Avenue. A760-ft-long main spanthe longestconcrete box girder span in the UnitedStatesresulted from the need to locatethe main piers outside the main channelof the Kanawha River in order to avoidinterference with barge traffic.

    The eight-span structure has spanlengths of 144, 247, 295, 295, 460,

    760, 540, and 209 ft for a total lengthbetween centerlines of abutmentbearings of 2950 ft. Spans 1, 2, 3, 4,5, 7, and 8 have a curved alignmentincluding a circular curve with a 1910 ftradius and a spiral transition. The main

    span has a tangent alignment.

    A continuous concrete box girdersuperstructure, using cantilever con-struction, was chosen for the full lengthof the bridge. This allowed for longerapproach spans, which reduced thebridges environmental impact.

    Given the size and urban setting ofthe project, bridge aesthetics werean important design consideration.The bridge concept was developed to

    be compatible with both the existingsteel plate girder bridge that will carrywestbound traffic and a future twinparallel westbound bridge.

    speeThe bridge cross-section accommodatesthree travel lanes, one auxiliary lane,and shoulders for a total roadwaywidth of 64 ft. The cross section of thesuperstructure consists of a single cellbox with inclined webs. The structural

    depth varies along the main span from38 ft at the piers to 16 ft at midspan.The bottom slab thickness is variablewith a maximum thickness of 5 ft at themain span piers and a minimum of 9 midspan. The approach spans have a

    constant depth of 16 ft and a constantbottom slab thickness of 9 in., with theexception of the pier tables where thebottom slab thickness transitions to 1 ft9 in. The webs have a constant thicknessof 1 ft 6 in.

    The top slab has constant dimensionsfor the full length of the bridge. Itsthickness varies transversely from aminimum of 9 in. to a maximum of 2ft at the intersection with the webs.The maximum 2-ft depth of the top

    slab is required to accommodate thecantilever tendons needed for themain span. The box girder cross sectionhas variable superelevation from plusto minus 8%. The specified concretecompressive strength is 6500 psi at 28days. For mass concrete, the acceptanceage was extended to 56 days.

    The concrete box section is post-tensioned longitudinally, transversely,and vertically. The longitudinal post-

    The twin-walled

    piers support the

    main span. While

    strong enough

    to support the


    construction, they

    are adequately

    flexible to




    asPire, w 2009|31

  • 8/7/2019 bridge pics


    tensioning consists of two sets oftendons. The cantilever tendons, locatedin the top slab, are stressed duringcantilever construction shortly after a newsegment is added. The span tendons,located in the bottom slab, are used inthe central part of the spans to providecontinuity between adjacent cantilevers.Transverse post-tensioning is utilized inthe top slab. Vertical post-tensioningconsisting of high strength 13/8-in.-diameter bars is required in the webs,in the proximity of the piers, where theshear forces are high. The post-tensioningwas designed to limit the principal tensilestresses in the webs.

    The continuous box girder will haveexpansion joints at the abutments only.

    The advantages of this design approachare to reduce maintenance, improveserviceability, and simplify construction,as intermediate hinges are not needed.The superstructure is fixed at the mainpiers and is supported on unidirectionalbearings at the approach piers andabutments. The bearings restrain thetransverse displacements while allowing

    longitudinal d isp lacements. Twobearings are provided at each pier withvertical service capacities up to 6900kips. The bearings will be blocked duringconstruction and the superstructure willbe temporarily fixed to the approachpiers. A large modular expansion jointwith a displacement capacity of 30 in.accommodates displacements causedby temperature, creep, and shrinkageat the west abutment. The eastabutment requires a joint with a 16-in.-displacement capacity.

    sbeThe main span piersPiers 5 and6consist of twin concrete walls, whichframe into the superstructure. Thetwin pier walls provide the necessarystrength and stiffness during cantileverconstruction and, at the same time, arelongitudinally flexible to accommodatedeformat ions caused by c reep,shrinkage, and temperature changes.The approach piersPiers 1, 2, 3, 4,and 7have a rectangular section with45-degree chamfers.

    The foundations consist of reinforcedconcrete footings and concrete drilledshafts socketed in the underlying hardsandstone. The average length ofdrilled shafts is about 45 ft. Two pre-construction drilled shaft load tests,using the Osterberg method, wereperformed prior to final design. Thesetests verified the ultimate end bearingand side shear capacity to be used.

    cThis project was advertised in February2007 using competit ive b iddingbetween the segmental concrete boxgirder alternative designed by T. Y. LinInternational and a steel box girdersuperstructure with the same spanarrangement that was developed byanother consultant.

    The contract was awarded to BraymanConstruction Corp. with a low bid forthe concrete alternative of $82,864,247.The low bid for the steel box alternativewas $112,910,000. The constructioncontract includes a small amount ofroadway work, MSE walls, and minorchanges to the existing bridge. Theseitems were the same for the steel andconcrete alternatives. The segmental boxgirder superstructure was designed to bebuilt by the balanced cantilever methodusing cast-in-place segments supported

    by two pairs of form travelers. Theproject has a total of 160, 16-ft-long,cast-in-place segments in seven pairs ofcantilevers. Falsework is required to castthe pier tables and the end segmentsnear the abutments.

    Bridge constructionscheduled tobe completed by the end of 2010has sparked local attention, which isexpected to peak in the summer of2009 with the closure of the mainspan cantilevers. When completed,

    area commuters will enjoy significantimprovements in safety and trafficcapacity in this segment of I-64.____________

    Santiago Rodriguez is an associatevice president of T.Y. Lin International,Alexandria, Va., and served as projectmanager and lead bridge designer for theKanawha River Bridge Project.

    For mor formto o ts or otr

    projcts, st .sprbr.or.

    In addition to the Kanawha River, the bridge

    crosses three roads and a railroad.

    Photo: Ahmed Mongi, WVDOT.

    32| asPire, w 2009


    The proposed segmental box girder bridge is a harmonious design with simpleand consistent forms with the same basic cross section between abutments.The selected cross section, with long overhangs and inclined webs, will resultin a light appearance. The shadow created by the overhang will reduce theperceived superstructure depth. The inclination of the webs will lessen thevolume of the superstructure. The curved approach spans will give a sense ofopenness and continuity with the graceful main span. The edges of the mainspan piers embrace the webs of the superstructure, thus subdividing the boxgirder depth. The piers have a modified rectangular section, with 45-degreechamfers, which reduce the perceived width of the columns in skewed views.A textured architectural treatment is used in the transverse faces of all piersand abutments. An applied concrete finish will be used on the surfaces of thesubstructure and superstructure elements
  • 8/7/2019 bridge pics


    Bridge MonitoringKnow more about your bridges.


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    acquisition systems for any size of bridge. From short-term testing

    to long-term monitoring, our systems can provide you

    with valuable decision-making data.

    asPire, w 2009|33

    American Coal Ash Association

    The American Coal Ash Association (ACAA) is devoted to educating engineers, concrete proessionals, standards organizations, and othersabout coal combustion products or CCPsmaterials produced by coal-ueled power plants. These include y ash, bottom ash, boiler slag,

    and ue gas desulurization materials. Fly ash concrete has been specifed because o its high strength and durability or numerous bridge

    projects worldwide, including the longest cable-stayed bridge in North America, the John James Audubon Bridge near Baton Rouge, La.

    The I-35W bridge near Minneapolis, Minn. has been reconstructed using a unique mix design that included y ash concrete to ensure

    a long-lasting, high perormance structure. Caltrans required high volume y ash mixes or the largest bridge project in its historythe

    San Francisco-Oakland Bay Bridge. Using innovative specifcations and blending techniques, Caltrans was able to improve its workability,

    hardening, and permeability properties o the bridges concrete. A number o engineering standards and specifcations defne CCP

    applications, thus ensuring high quality perormance and products.

    Though these materials properties vary according to coal composition and power plant operating conditions, experts can advise on

    quality and determine the best mix design or most any condition and project. Mix designs exceeding 40 percent y ash have proven

    successul in many projects. Experts with frst-hand experience may be located by contacting ACAA. The technical, environmental and

    commercial advantages o CCPs contribute to global sustainability.

    In addition to a myriad o core perormance attributes in sustainable construction, CCP use can conserve natural resources, reduce

    greenhouse gas emissions and eliminate need or additional landfll space. For more inormation, contact ACAA at [email protected]

    or call 720-870-7897.[email protected]:[email protected]://
  • 8/7/2019 bridge pics

    5/9Web| ASPIRE, Winter 2009


    Comprising a total of seven approach spans, the bridges total length is 2975 ft. Illustration: T.Y. Lin International.

    The concrete box girder in the approach spans measures

    64 ft wide and 16 ft deep. Photo: T.Y. Lin International.

    The segmental box girder bridge is a harmonious design.

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    6/9ASPIRE, Winter 2009|Web


    Photos: T.Y. Lin International.

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    7/9Web| ASPIRE, Winter 2009


    Photos: T.Y. Lin International.

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    8/9ASPIRE, Winter 2009|Web


    Photo: Ahmed N.K. Mongi, of the WVDOT.

    Work continues on the Kanawha River Bridge with completion expected

    by the end of 2010. Photo: Ahmed N.K. Mongi, of the WVDOT.

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    9/9Web| ASPIRE, Winter 2009


    Photo: Ahmed N.K. Mongi, of the WVDOT.