Cowen Park Bridge Seismic Retrofit

November14, 2019

What's happening now?

Our project team has finalized the design for the Cowen Park Bridge Seismic Retrofit and a contractor has been brought onboard to complete the work. Construction is anticipated to begin as early as November 11, 2019 and last approximately 6 months. 

In order to safely replace the expansion joints, we will need to temporarily close the bridge. We currently anticipate up to 3 weekends of full bridge closures scheduled for spring 2020. We will be in touch with the nearby community to share information about the anticipated closure dates and detour route closer to construction. Please note that the construction schedule is subject to change based on site conditions, material and equipment availability, weather, and other factors.

To stay up-to-date with the latest project information, sign up to join our project listserv. 

Construction Impacts

Construction is anticipated to begin this winter and last approximately 6 months. Most of the work will take place underneath the bridge. We will strive to minimize construction impacts as much as possible. During construction, please expect:

  • Regular weekday work hours of 7 AM - 5 PM, Monday through Friday
  • Redirects for people walking and biking across the bridge
    • People walking across the bridge will be directed to one side of the bridge while we work on the other side of the bridge
    • People biking will merge with traffic for the duration of construction
  • 3 weekend full bridge closures and detours. We will post detours and notify nearby homes 72 hours in advance.
  • Temporary closure of the upper trail underneath the bridge within Cowen/Ravenna Park
  • Noise, dust, and vibrations during work hours. We will be monitoring bridge vibrations throughout construction.
  • Equipment and construction materials near the site, including trucks using the access road to the west from Brooklyn Ave NE, to move materials and equipment in and out of the work zone

We'll continue to provide updates about the construction start date, timeline, and impacts via our project listserv

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

Cowen Park Bridge Seismic Retrofit

The planned seismic retrofits to the Cowen Park Bridge include 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   Winter 2018
  Final Design   Spring 2019
  Construction begins   Winter 2019
  Completed retrofits  Summer 2020

*The schedule is subject to change

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.

Get involved

We're committed to keeping you informed and working with neighbors to limit construction impacts to the extent feasible. Here are some ways to get more information about the project:

  • Email the project team at CowenParkBridge@seattle.gov
  • Leave a voicemail at 206-775-8734. A project representative will return your call. 

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 happening from NE 55th St to Lake City Way. We will be working closely with this project team to understand community impacts from both projects during construction in 2019. This will help us minimize impacts as much as possible as we work on the bridge. We will continue to do our best to minimize traffic delays, detours, and construction impacts. 

Project Materials