Novelty Bridge King County Department of Transportation
HWA GeoSciences Inc. performed geotechnical design studies and assisted in construction of the new bridge in eastern King County, Washington. The new bridge is a 620-foot long, 5-span structure crossing the Snoqualmie River, which replaced an old, failing structure. The geotechnical work included evaluation of subsurface conditions, and development of final design recommendations for foundation support including use of deep foundations to provide adequate support in soft/loose soil conditions. The presence of loose saturated sand deposits beneath the bridge represented a liquefaction hazard that had to be mitigated in bridge design. Recommendations were provided for ground improvement using stone columns to mitigate liquefaction hazard and the potential for lateral spreading to impact the bridge abutments. The study also addressed settlement of bridge approach fills, scouring protection and provided recommendations for surcharging. HWA provided assistance during pre-construction planning meetings to determine risks and impacts of underground obstructions and to develop standard procedures when obstructions were encountered. This preparedness proved invaluable to maintain the strict schedule to re-open the new bridge. HWA provided continued geotechnical design services during construction of the new bridge. Our services included monitoring and inspection of the installation of stone columns and 24” diameter steel pipe piles.
Other Notable Projects:
Interstate 5/196th Street SW Interchange City of Lynnwood, Community Transit and Washington State Department of Transportation
Pacific Avenue Overcrossing City of Everett
State Route 510 Overcrossing Washington State Department of Transportation
Weller Street Pedestrian Bridge King County Department of Transportation
Denny Way/Lake Union CSO King County Department of Natural Resources
Eastside Interceptor King County Department of Natural Resources
HWA GeoSciences Inc. performed geotechnical design studies and assisted in construction of the new bridge in eastern King County, Washington. The new bridge is a 620-foot long, 5-span structure crossing the Snoqualmie River, which replaced an old, failing structure. The geotechnical work included evaluation of subsurface conditions, and development of final design recommendations for foundation support including use of deep foundations to provide adequate support in soft/loose soil conditions. The presence of loose saturated sand deposits beneath the bridge represented a liquefaction hazard that had to be mitigated in bridge design. Recommendations were provided for ground improvement using stone columns to mitigate liquefaction hazard and the potential for lateral spreading to impact the bridge abutments. The study also addressed settlement of bridge approach fills, scouring protection and provided recommendations for surcharging. HWA provided assistance during pre-construction planning meetings to determine risks and impacts of underground obstructions and to develop standard procedures when obstructions were encountered. This preparedness proved invaluable to maintain the strict schedule to re-open the new bridge. HWA provided continued geotechnical design services during construction of the new bridge. Our services included monitoring and inspection of the installation of stone columns and 24” diameter steel pipe piles.