TYLin developed a seismic retrofit solution for the Coronado Bay Bridge in San Diego, California.
The Coronado Bay Bridge is a main toll bridge that crosses over San Diego Bay to link San Diego with Coronado. This bridge is important to the economic and social vitality of the state of California. It also provides a critical avenue for emergency response and subsequent regional recovery following a large seismic event.
To maintain the structure’s reliable seismic performance, TYLin developed a seismic retrofit strategy and designed the retrofit for the California Department of Transportation Division of Structures. The solution addressed the structural needs and satisfied the community and commercial interests.
The structure includes 29 steel spans plus three precast/prestressed I-girder spans on the San Diego side of the Bay for a total length of 7,824 feet. The bridge has three main channel spans of 660, 660, and 560 feet consisting of steel box girders with an orthotropic deck. The remaining steel spans are welded plate girders with a lightweight concrete deck.
The bridge alignment is on a tangent from the San Diego end, heading southwest toward Coronado. Between Piers 17 and 4, the alignment curves to the north through a full 90 degrees.
- Scope of work included verification of seismic vulnerability studies, component analysis, and independent checking of the final retrofit strategy.
- Several unique retrofit solutions were proposed to address community concerns, including preserving historically and culturally significant murals on the east approach ramps.
- Retrofit measures included seismic isolation, hinge restrainers, viscous dampers, and strengthening of pier caps, columns, and pile caps.
- TYLin also designed the retrofit of five concrete girder approach ramp structures.
- The TYLin team provided plans, specifications, and cost estimates for the final retrofit design.