The Seattle DOT (SDOT) recently announced that crews are hard at work designing the full rehabilitation work (phase 2) for the West Seattle High-Rise Bridge, after completing the phase 1 stabilization effort.
In December 2020, SDOT completed the stabilization measures for the bridge and lowered all work platforms. For the next phase of rehabilitation, the goal is to reach the preliminary design milestone this month.
SDOT said that while the agency has designed the stabilization measures to perform well at all temperatures, crews need to observe how the now-stabilized high bridge responds to seasonal temperature changes, particularly changes from colder to warmer weather. The intelligent monitoring system installed in May 2020 is helping to do this. The system is a combination of movement sensors, crack monitors, and cameras that allow us to see inside the bridge and help to provide real-time data to our teams.
The agency is also beginning the process of selecting a contractor who can help to take bridge rehabilitation across the finish line. SDOT plans to bring the contractor on during the bridge design phase, aiming to get a contractor on board by summer.
Although still in the process of designing the full rehabilitation, the team is using several standard construction methods in its efforts to ready the high bridge for traffic to return in 2022. Crews used epoxy crack filling, carbon-fiber wrapping, and post-tensioning to stop the progress of the cracking and stabilize the bridge in phase 1. Full bridge rehabilitation will likely continue this work and could include more post-tensioning and carbon-fiber wrapping—methods that phase 1 has shown can help strengthen the bridge and reduce further cracking.
More updates on the West Seattle High-Rise Bridge can be found on SDOT's blog.
SOURCE: Seattle DOT