Overview
From October 2007 to April 2008, we strengthened four column footings between Columbia Street and Yesler Way to prevent further sinking.
Crews drilled a series of steel rods surrounded by concrete into stable soil, and added a layer of reinforced concrete to tie the new supports to the existing column footings.
Why did we pursue this project?
The viaduct section between Columbia Street and Yesler Way had settled approximately five-and-a-half inches into the ground since the 2001 Nisqually earthquake. Engineers determined that the trend of continued settlement made it a prudent decision to move forward with repairs. We continue to closely monitor any further deterioration.
The end result
This project limits settlement in this area of the viaduct and prevents further damage to the structure. This is a temporary repair that allows the viaduct to remain open for traffic until we begin to replace it along the central waterfront.
Updated September 2008