Concrete Products covers the issues that attract producers of ready mixed and manufactured concrete focusing on equipment and material technology, market development and management topics.
Issue link: http://concrete.epubxp.com/i/194286
FEATURE COVER STORY PIER LESS The bridge abutment is located on the northwest side of a roadway realigned with slightly more skew to the rail line than its predecessor. Superstructure loads are distributed across a cast-in-place girder seat, steel H piles driven to bedrock, 9,300 yd. of abutment fll, and the MSE panels. ODOT elected to expand an existing abutment as a means of eliminating the original structure's second span. Construction of a pier was subject to environmental impact review owing to a waterway that resembles more of creek than a river at U.S. 30. The BT90 girders enabled a single span meeting UPRR vertical and ground clearance requirements. Roadway realignment, abutment expansion and a switch from the original replacement bridge design—two spans with 120-ft. prestressed girders—afforded ODOT and Hamilton Construction ample savings to cover shipping and additional crane costs associated with the precast concrete specs. The new structure succeeds a bridge completed in 1922, with main steel through-truss span and cast-in-place, reinforced concrete deck girder approach span. PHOTOS: Ted Burney, ODOT Photo and Video Services PHOTOS: Ted Burney, ODOT Photo and Video Services Projects dating to 2005 have fueled ODOT and Hamilton Construction's confdence in the Oregon Bulb Tee 90 super girder, well suited to spans in the 160- to 185-ft. range. One of four BT90s Knife River Northwest fabricated for Hamilton is shown en route to the Burnt River jobsite. New on the precast schedule for the U.S. 30 crossing were precast deck panels, cast along with the girders at Knife River NW's Harrisburg, Ore., plant. ODOT capitalized on two mainstays in precast to realign the U.S. 30 Union Pacifc rail line and Burnt River crossing and eliminate the need for a replacement pier: long-span bulb tee prestressed girders bearing on an abutment supported by precast mechanically stabilized earth panels. www.concreteproducts.com The U.S. 30/Burnt River bridge lies between two Interstate 84 interchanges; closure meant a seven-mile detour. The limited traffic disruption factor, lower potential for schedule delays attributable to the precast girders and MSE panels, plus relatively simple construction scheme, spelled a good opportunity to test precast deck panels. That specification and proposed use of ultra high performance mixes for cast-in-place connections, in turn, helped garner a $500,000 FHWA program grant, according to ODOT Region 5 Tech Center's George Bornstedt, P.E., interim Bridge-Environmental– Geo-Hydro manager. Continued on page 30 October 2013 • 29