Admiral Way North and South Bridges Seismic Retrofit

Updated September 2025

Retrofits to help the Admiral Way North and South Bridges better withstand earthquakes are complete!

Four views of the Admiral Way Bridge. Top left: a close-up of the roadway with expansion joint and green railing. Top right: the sidewalk and railing along the bridge next to nearby houses. Bottom left: the underside of the bridge showing steel supports on a steep slope. Bottom right: a long view of the bridge deck with two travel lanes and a sidewalk.

Here’s what we’ve done to make the bridge stronger and less vulnerable in the event of an earthquake:

  • Concrete Crack and Spall Repair: Throughout the bridge, crews have repaired concrete cracks and spalls. Concrete cracks and spalls can reduce bridge integrity and life span, fixing them is very important to keep the bridge in good condition.

  • Carbon-Fiber Wrapping: After the concrete repair, we installed carbon fiber wrapping to strengthen the bridge’s crossbeams, columns, and piers. This lightweight composite material increases the strength and adds a protective layer to the bridge components, helping the bridge be more resilient in a seismic event. 

  • Installed and Replaced Components: As part of the seismic retrofit, crews strengthened the bridges by installing a shear key, retrofitting floor beams, and adding a concrete infill wall to reinforce the truss, making the bridge more resilient during a seismic event. They also replaced gusset plates and expansion joints, and added buckling-restrained braces to improve seismic performance. They strengthened the north deck with a continuous reinforced concrete chord to better withstand lateral rotation during earthquakes. 

  • Corrosion Repair and Prevention: Crews repaired corrosion damage on support structures under the bridge and painted the steel components of the bridge to reduce further corrosion damage.

  • Slope Strengthening and Stabilization: Crews installed drilled shafts at both ends of the bridge and soil nails on the slopes below the bridge to make slope more secure. This improvement will strengthen the bridge’s resiliency to seismic events like earthquakes. During this slope stabilization work, our crews also installed new landscaping.

Side-by-side view of bridge columns before and after work, showing slope stabilization with rock and fencing, and reinforced concrete columns.
Caption: We’ve strengthened the bridge by reinforcing its columns, stabilized the slope, and improved the surrounding landscape for long-term resilience.

About the Project

Seattle is located in an earthquake-prone region, and earthquakes can seriously impact our bridges. To address this risk, the City of Seattle created the Bridge Seismic Program to evaluate which bridges are vulnerable and reinforce them to better withstand seismic events.    

As part of the Levy to Move Seattle, 16 bridges were selected for seismic retrofits, including the Admiral Way North and South Bridges. The Admiral Way North and South Bridges are older bridges built prior to modernizing the seismic design code.  

The bridges are on SW Admiral Way between 39th Ave SW and Walnut Ave SW, above Fairmont Ave SW. While it seems like one bridge when you’re traveling on it, the Admiral Way North and South Bridges are actually two bridges, side-by-side. Both were retrofitted, making them stronger and safer in the event of an earthquake.  

Project Area

The bridges are on SW Admiral Way between 39th Ave SW and Walnut Ave SW, above Fairmont Ave SW.

Admiral Way BSR Overview map showing cloures

Project Schedule

Design Complete
Construction Complete
Project Completion Summer 2025

Funding

The project is funded through the Levy to Move Seattle. 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. In addition, this project has received federal funding. 

Project Materials

Translation and interpretation 

  • If you need this information translated, please call (206) 775-8734
  • 如果您需要此信息翻譯成中文 請致電 (206) 775-8734
  • Kung kailangan mo ang impormasyon na ito na nakasalin sa Tagalog mangyari lamang na tumawag sa (206) 775-8734
  • Si necesita traducir esta información al español, llame al (206) 775-8734
  • Odeeffannoon kun akka siif (206) 775-8734
  • Nếu quý vị cần thông tin này chuyển ngữ sang tiếng Việt xin gọi (206) 775-8734
  • የዚህን መረጃ ትርጉም ከፈለጉ፣ በዚህ ስልክ ቁጥር ይደውሉ፡ (206) 775-8734
  • ናይዚ ሓበሬታ ትርጉም እንተደሊኹም፣ በዚ ቁጽሪ ስልኪ ይድውሉ፡ (206) 775-8734
  • 당신이 번역이 정보를 필요로하는 경우에, (206) 775-8734? 전화 해주십시오. 
     

Transportation

Adiam Emery, Interim Director
Address: 700 5th Ave, Suite 3800, Seattle, WA, 98104
Mailing Address: PO Box 34996, Seattle, WA, 98124-4996
Phone: (206) 684-7623
684-Road@seattle.gov

Newsletter Updates

Subscribe

Sign up for the latest updates from Transportation

The Seattle Department of Transportation (SDOT) is on a mission to deliver a transportation system that provides safe and affordable access to places and opportunities for everyone as we work to achieve our vision of Seattle as a thriving, equitable community powered by dependable transportation.