FHWA > Bridge > PBES > Bridge Deck Replacement Project Using Self-Propelled Modular Transporters (SPMTs) |
Bridge Deck Replacement Project Using Self-Propelled Modular Transporters (SPMTs)Project Name & LocationLewis and Clark Bridge, SR 433 over Columbia River between Washington & Oregon Bridge Type, Span Configuration, & Overall Weight1929 historic steel truss bridge with a total bridge length of 5,478 ft (3 deck truss spans at 168 ft, 337 ft, 337 ft; 3 through truss spans at 760 ft, 1200 ft, 760 ft; plus approach spans), of which 3900 ft of the deck was replaced with 103 prefabricated deck panels that were 36 ft wide x 20 ft to 45 ft long (20 at 45 ft, 45 at 40 ft, 20 at 35 ft, 14 at 30 ft, and 4 at 20 ft). The panels were 6-in. thick plus 1-in. thick overlay and had a maximum panel weight of 96 tons. Movement Dates & TimesSeptember 2003 through February 2004. Full closures were allowed between 9:30 p.m. and 5:30 a.m. for only 120 nights, plus 4 weekend closures. One panel was replaced per night in a 6-hr move. The contractor earned a bonus of $185,000 for early completion. Project DescriptionThis was a joint project by the Oregon Department of Transportation (ODOT) and the Washington State Department of Transportation (WSDOT) to widen and replace the deteriorating deck with a full-depth precast concrete deck, while maintaining full rush-hour traffic. WSDOT designed the prefabricated full-width deck panels and a placement procedure to accommodate the required rapid construction. The contractor revised the placement procedure using self-propelled modular transporters (SPMTs) with a specially designed steel truss frame for lifting and transporting that enabled him to meet the scheduling constraints. The SPMTs moved the new panel to the top of the bridge, removed the old panel that crews had just cut out, and then lowered the new panel into place before taking the old panel off the bridge. The majority of the existing bridge deck was replaced with 103 precast concrete deck panels made of 120 lb/cu ft lightweight concrete with a modified concrete overlay supported by two longitudinal steel stringers with intermediate transverse stringers. No post-tensioning was used. The bridge also used prefabricated widening sections supported by a single longitudinal steel girder. In addition, the project included precast approach slabs. ODOT and WSDOT extended the life of the bridge by an estimated 25 years. In addition, prefabrication allowed inspection of the new deck before installation without use of specialized equipment. For Max J. Kuney Company of Spokane, use of prefabricated elements and systems reduced workers exposure to traffic during construction and improved the constructability of the bridge. Use of prefabrication allowed the bridge to remain open for normal weekday operation, particularly important for traffic to and from the Port of Longview. Average Daily Traffic (ADT)The ADT for the Lewis and Clark Bridge is 18,000. Detour LengthThe detour length was 40 miles going west to Cathlamet and involved a ferry ride across the Columbia River (ferry at this location is small and slow). The other option was to go south to Portland, an 80-mile trip. Since these detours were so long and the bridge was closed all night for each panel placement, a helicopter with a landing pad was provided on the south side of the river. It was used a number of times for medical emergencies and a few child births. User Delay Cost for Closing the BridgeA user delay cost was not calculated. Incentive/Disincentive ProvisionsThe provisions in the contract documents are detailed below. Incentives
Disincentives
Project Contact Name, Title, Company, Phone & EmailJ. A. Weigel, P.E., S.E. Project RequirementsApplicability of SPMTs for delivery and removal of deck units is dependent on site-specific constraints, and should be discussed with SPMT suppliers in the early planning stage. Note in contract documents might read to the effect, "Use of a modular transport system that can remove old deck sections and install new deck sections in the same operation will be allowed, similar to the Lewis and Clark Bridge deck replacement project near Longview, Washington." SPMT Usage CostApproximate cost range for use of SPMTs to lift old panel out, lower new panel in, and haul old panel off bridge is $15,000-$25,000 per maximum 45 ft x 45 ft panel. SPMT Suppliers
Lewis and Clark Bridge Full-width panel lifted and suspended in specially-designed steel truss frame. SPMTs transporting new deck panel from fabrication site adjacent to bridge. SPMTs with new deck panel approaching panel installation location on bridge. |
EventsMore InformationContactVasant Mistry |
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This page last modified on 05/12/08 |