Newly reinforced columns under NE 45th Viaduct E approach.
It’s critical to emergency response and a key University-to-University Village connection–now the NE 45th St Viaduct has the full seismic effect. The project to seismically retrofit the east approach started in March of 2018 and recently wrapped up. Most of the work took place under the bridge, reinforcing columns with more resilient structures then restoring disturbed landscapes.
2018: NE 45th Viaduct E approach seismic improvements.
Final segment of retrofit.
The east approach was the last segment of the NE 45th St Viaduct seismic retrofit, which began in the 1990s! The structure was originally built in 1938 and its west approach was one of the last remaining wooden trestle bridges in Seattle. A 1981 photo even shows wooden railings.
West approach timber trestle prior to replacement.
1981: NE 45th Viaduct W approach.
Over the years, the City has widened and reconstructed segments of the NE 45th St Viaduct to improve Seattle’s transportation system and maintain an important E/W connection in the ever-growing Seattle.
3 Phases of retro.
The whole viaduct improvement process began when the City implemented a pilot program to evaluate and retrofit bridges identified as seismically vulnerable. The NE 45th St Viaduct was one of those bridges, then retrofitted in 3 phases: the west approach; the main spans; and the east approach.
Enhancements over the years include:
2010: W approach timber trestle replacement in progress.
- Replacing the viaduct’s timber trestle with a structural earth wall at W approach.
- Construction of a concrete roadway.
- Construction of seismic restrainers; foundation strengthening for main spans.
- Construction of seismic restrainers, catcher blocks, Fiber Reinforced Polymer strengthening, and piers walls at E approach.
All improvements implemented for the NE 45th St Viaduct to make it more seismically resilient bridge!
2010: Rebuilt W approach.
The bridge team…
We are committed to improving and maintaining our bridges throughout Seattle. Visit the SDOT Bridges webpage to learn more about our current bridge projects. Thank you, everyone, for your patience over the years and support for bridge maintenance!
