NE 45th St Viaduct Project – East Approach Seismic Retrofit

Project Description

In the early 1990s, we implemented a program to evaluate and retrofit bridges that were identified as seismically vulnerable. The NE 45th St viaduct’s east approach was identified as one of those seismically vulnerable bridges and needs to be retrofitted. Retrofitting the east approach will make the bridge more structurally resilient to seismic events.

The NE 45th St bridge is an important connection between the University District and University Village and an important emergency route. It was built in 1938 and over the years, we’ve widened and reconstructed segments of the viaduct. In the mid-1990s, the main span was seismically retrofitted. The west approach was fully reconstructed in 2010. The east approach seismic retrofit is scheduled to begin this fall (see graphic below).

Historic photo

The impact of retrofitting the east approach will be smaller and more localized than the reconstruction of the west approach. Most of the work will take place underneath the bridge with minimal disruptions for people driving or walking. Retrofitting the east approach includes:

  • Placing steel jackets on the bridge columns
  • Installing longitudinal and transverse restraints underneath the bridge
  • Constructing in-fill walls between existing columns
  • Constructing a new catcher bent along one of the existing expansion joints
  • Restoring disturbed landscaping  
Columns supporting bridge #1 Columns supporting bridge #2

This project is currently in design. As we get closer to finalizing the design, we’ll engage businesses and residents about potential impacts to traffic and pedestrian walkways.

Project Budget & Funding

Total project budget: $2 million

Funding Sources:

  • Federal funds (FHWA)
  • Local funds (Street Vacations)

Project schedule*

60% Design submittal


90% Design submittal

Early 2017

Final Design submittal

Spring 2017

Advertise for a contractor

Summer 2017

Construction begins

Fall 2017

* The schedule is subject to change.

Project Map

Project map

Questions or Comments?

Adonis Ducksworth
Project Communications Lead
(206) 684-4193

Kit Loo, PE
Project Manager, SDOT