Precast, prestressed concrete girders with acast-in-place deck were the obvious choice.Superstructure<strong>The</strong> superstructure selection was heavilyinfluenced by the RFP’s requirementthat the typical span length of thebridge had to be a minimum of 130ft and the channel span length hadto be a minimum of 250 ft. This spanarrangement, and the aggressiveenvironment created by the saltwater inEscambia Bay, made precast, prestressedconcrete girders with a cast-in-place deckthe obvious choice for the superstructure.For the typical span, five 78-in.-deepFlorida bulb tees at a 12 ft 6 in. spacingand a length of 136 ft were the mosteconomical. A three-span post-tensionedspliced girder based on the 78-in.-deepFlorida bulb tee was chosen for thechannel span.<strong>The</strong> spliced girder is comprised of fivesections: two haunched sections overthe center piers, two end sections, anda drop-in girder between the haunchedsections. <strong>The</strong> haunched sections overthe center piers increase to a maximumdepth of 112 in. <strong>The</strong> system contains fourdraped post-tensioning ducts to housetwelve 0.6-in.-diameter Grade 270 lowrelaxationstrands. To handle the burstingstresses associated with these strands,the end beams contain an approximate2-1/2-ft-wide by 10-ft-long anchor blockover the full depth of the beam.A deck stripper was used to remove thesteel formwork from the underside ofthe deck.Before erection of the segmentscould occur, two temporary shoringtowers were constructed to supportthe system between the end girdersand the haunched girders. After thehaunched and end girders were erected,the drop-in section was set into placebetween the haunched girders. <strong>The</strong>drop-in segment rested on two strongbackssupported from the tops of thehaunched girders. Once all the segmentswere in place, the strands in the firsttwo post-tensioning ducts were stressed.At this point, the deck was placed. Afterthe deck achieved sufficient strength,the strands in the last two ducts weretensioned. This erection sequenceafforded minimum disturbance to thebarge traffic in the channel.Deck ConstructionAfter the girders were set anddiaphragms cast, work shifted to theCIP deck. Two methods were employedfor the placement of formwork utilizedin the deck construction. <strong>The</strong> first wasa removable steel formwork system,which was installed with a track-drivenformwork placer. <strong>The</strong> tracks for theplacer were temporarily placed on thegirders. <strong>The</strong> placer used a system ofwinches to lift formwork, drive it intoposition, and hold it in place as workerstightened a series of turnbucklesto allow the formwork to rest on thebottom flange of the girders. Aftercasting the deck, the formwork wasremoved by a formwork stripper. <strong>The</strong>stripper drove over the deck on rubbertires and employed an under-slung armto access the formwork from belowthe deck. <strong>The</strong> stripper used a system ofhydraulic jacks, winches, and a slidingplatform to remove the formwork andtransport the sections to the top ofthe deck for future use. At the peak ofconstruction, this method allowed thecontractor to place over 10,000 ft 2 ofbridge deck per day.<strong>The</strong> second formwork method utilizedwas corrosion resistant stay-in-place (SIP)forms. <strong>The</strong> use of SIP was approved forthe approaches and over the channel toallow deck construction from multiplefronts.A track-driven placer was used to installthe steel formwork for the deck.Working on multiple fronts wasnot unique to deck construction.<strong>The</strong> extremely aggressive scheduleassociated with the project requiredthe contractor to utilize this philosophyon all aspects of construction. At thepeak of construction, over 20 craneswere on site with a work force of over350 people working day and night tocomplete the first bridge.ConclusionInterstate 10 provides the travelingpublic with a vital link between Floridaand the southeastern United States. I-10functions as a major corridor for thedelivery of goods and services, and alsoas an essential evacuation route. <strong>The</strong>importance of reestablishing this linkcould not be said more simplisticallyand truthfully than as stated by theformer governor of Florida, Jeb Bush,at the ribbon cutting ceremony for theeastbound bridge, “This was a big damndeal!” <strong>The</strong>se bridges will stand as atestament to what can be accomplishedwhen a crisis challenges the tenacityand perseverance of the bridge buildingcommunity.___________________Charles Rudie, senior structural engineer;John Poulson, vice president; VictorRyzhikov, senior supervising engineer;and <strong>The</strong>odore Molas, senior structuralengineer are all with PB Americas,Tampa, Fla.For more information on this or otherprojects, visit www.aspirebridge.org.24 | <strong>ASPIRE</strong>, <strong>Summer</strong> 20<strong>08</strong>
HPC <strong>Bridge</strong> Views Is Now Electronic OnlyStarting in 20<strong>08</strong>HPC <strong>Bridge</strong> Viewswill be distributedelectronically.To continue to receiveHPC <strong>Bridge</strong> Viewsyou must subscribeonline at:Newwww.hpcbridgeviews.orgDon’t miss any more issues.Subscribe today.U.S. Department of TransportationFederal Highway AdministrationTMconcretethe sustainablemedium of tomorrow’senvironmentArchitectural <strong>Concrete</strong>.<strong>The</strong> versatile building product for:• DURABILITY AND LONGEVITY• ENERGY EFFICIENCY• REFLECTIVE SURFACES• BETTER INDOOR AIR QUALITY• BEAUTIFUL & FUNCTIONAL STRUCTURESLEHIGH CEMENT COMPANYWHITE CEMENT DIVISION7660 Imperial WayAllentown, PA 18195-1040LehighCementis committedto sustainabledevelopment.Toll Free 1 800 523 5488Phone 610 366 4600Fax 610 366 4638www.lehighwhitecement.com<strong>ASPIRE</strong>, <strong>Summer</strong> 20<strong>08</strong> | 25
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