Repairs are required to this 70-year-old elevated roadway that connects Interstate 5 to the West Seattle Bridge. The new proposed bridge will provide access to surface streets from the upper Spokane Street roadway, reduce delays on the lower Spokane Street roadway at railroad tracks, and facilitate transit access between west and downtown Seattle. The new ¾-mile elevated structure includes drilled shafts, cast-in-place columns, bents, box beam girders, steel plate girders, precast concrete girders, and a structural earth wall. On-grade work includes concrete paving, asphalt paving, the replacement of five intersections, and new below-grade utilities.
PCL worked with the client to provide a no-cost change: choosing precast girders instead of cast-in-place mainline girders created additional public access to surface streets and an expedited schedule delivery. This innovative design change created value by relieving traffic congestion during construction. As part of the development of the revised design, the project team used 3-D modeling to communicate major work sequencing and materials movements, providing the client with enhanced planning benefits.