Spokane, Washington
US 395: NSC Sprague Avenue - Spokane River Phase 1
|
This is the first phase of the new Skyway Bridge connecting US 395 from I-90 to the Spokane River crossing. The Skyway Bridge, when it is complete, will carry traffic roughly two miles on elevated structure from I-90 across the Spokane River before returning traffic to grade on the north side of the river.
Phase 1 included the construction of two 1530-foot-long elevated road structures. The structures are prestressed concrete girder bridges, spanning the Spokane Community College (SCC) from Mission Avenue to Ermina Avenue. Each structure has nine 170-foot spans. The substructure is adorned with ornate concrete reliefs and architectural finishes. Hamilton utilized the early-stage procurement period to prepare several value engineering (VE) concepts for WSDOT to consider. With the help of a design consultant, Hamilton crafted a VE proposal that re-engineering the substructure to eliminate the 10-foot-diameter drilled shafts. By replacing the drilled shafts with spread footings, Hamilton could self-perform the work. Self-performing the work eliminated risky subcontractor work, reduced project costs by $1.8 million, and provided an opportunity to allow long-lead procurement items to catch up with on-site production. The VE solution leveled resources and provided uninterrupted workflow on-site. In addition, eliminating drilled shafts eliminated the potential for environmental impacts. WSDOT had set aside $1.4 million in a contingency fund for the project, which included funds to respond to issues arising from site conditions encountered by drilling shafts. Spread footings eliminated the need for the contingency fund and created a forward-thinking framework for how we want to approach bid-build work in Washington in the future. |
Major Project Elements
|
