Cowen Park Bridge Seismic Retrofit

Updated: May 7, 2020

What's happening now?

We've completed work on the Cowen Park Bridge seismic retrofit! These improvements will help strengthen the bridge to better withstand seismic events like earthquakes. Over the last six months, we 

  • Installed carbon fiber wrapping to strengthen the bridge's crossbeams, columns, and arches 
  • Strengthened the existing arch with concrete infill 
  • Installed concrete blocks and supportive shells for the bride's column's and crossbeams 
  • Repaired cracks and concrete damages 
  • Replaced the expansion joints at both ends of the bridge  

Completed seismic retrofit of the Cowen Park Bridge

Thank you for helping us improve the resiliency of the Cowen Park Bridge! If you have any remaining questions or concerns about the Cowen Park Bridge Seismic Retrofit project, please contact us at 206-684-ROAD (7623) or 684-Road@seattle.gov.

Project overview

Earthquakes could have a significant detrimental effect on Seattle's infrastructure. To address seismic risks to city infrastructure, the City of Seattle established a bridge seismic retrofit program to assess the seismic vulnerability of the City's bridges and to prioritize limited funding to reduce this transportation infrastructure vulnerability.

As part of the Levy to Move Seattle, 16 bridges were selected for seismic retrofits, including the Cowen Park Bridge. The Cowen Park Bridge is an older bridge built in 1936 prior to the modernization of the seismic design code. The bridge connects the Roosevelt/Ravenna neighborhood with the University District via 15th Ave NE across Cowen and Ravenna Park. 

Cowen Park Bridge Map

The seismic retrofits to the Cowen Park Bridge included several modifications to seismically strengthen existing bridge components and reduce overall seismic vulnerability. The following images show the major construction elements. Images shown are sample renderings to illustrate planned improvements. The off-white coloring in each image represents the planned seismic improvement after construction will be complete. Furthermore, each number in the rendering images display the type of improvement. If there are other off-white improvements not labeled in the image, then those are the same seismic improvement as the one that is labeled.

  1. Strengthen existing arch with fiber     wrapping

  2. Add concrete infill between columns

Underside of Cowen Park Bridge
  3. Add concrete blocks to support   beams   Underside of bridge
  4. Strengthen end of bridge support   columns with fiber wrapping Bridge columns

  5. Reinforce interior columns

  6. Strengthen support columns on arch   with fiber wrapping

Interior support columns of bridge

Project Schedule

  30% Design   Complete
  60% Design   Complete
  Final Design   Complete
  Construction began  Winter 2019
  Retrofit complete  Spring 2020

Funding

The total project estimate is $3.7 million, and the project is funded through the Levy to Move Seattle and a federal grant. Approved by voters in 2015, the 9-year, $930 million Levy to Move Seattle provides funding to improve safety for all travelers, maintain our streets and bridges, and invest in reliable, affordable travel options for a growing city. 

Nearby Construction Project

The Cowen Park Bridge is located over a ravine in Cowen Park along 15th Ave NE, where the 15th Ave NE Paving Project is underway from NE 55th St to Lake City Way. We worked closely with this project team to understand community impacts from both projects during construction in 2020.  

Project Materials