SR 167 Puyallup River Bridge Replacement
This design-build project replaced the existing historic landmark—a 1925 Warren Truss bridge—with a new wider northbound bridge that meets today's design standards. Atkinson's design differed from WSDOT's contract plans to build a new four-span concrete bridge to the west of the existing southbound bridge. Instead, we built a three-span, 557-foot-long steel girder bridge within the existing northbound Warren Truss bridge footprint. By doing so, Atkinson eliminated the proposed southbound widening and all retaining walls, utility relocation, ground improvement, and signalized intersection work. To accomplish this, we built new temporary piers and approach roadways and rolled the Warren Truss to the east for use as a temporary northbound detour. This also allowed us to maintain northbound traffic at current capacity during construction.
The steel bridge benefits included eliminating the in-water pier and fish window constraints on the schedule, providing flexibility for future master plan construction, and accommodating the future levee widening.
The geotechnical conditions at this site were extremely complicated. Site soil conditions consisted of fill soils underlain by an artesian aquifer and a very thick alluvial deposit that was subject to liquefaction, lateral spreading, and settlement during earthquakes. Our large-diameter drilled shafts were designed to withstand the soil and artesian water conditions and our abutment design improved global stability. Using rotator-oscillator drilling methods, Atkinson limited the risk of vibration-induced settlement on the existing structures and utilities. In addition, a web-based vibration and settlement monitoring system immediately notified our team if detrimental effects were detected.
Upon project completion, we removed the historic Warren Truss bridge intact and stored it northwest of the project site for WSDOT's future use.