Southgate Road Realignment at San Francisco – Oakland Bay Bridge, Yerba Buena Island

The Southgate Road Realignment Project extends the approach to the westbound on-ramp and eliminates stop control access; allowing I-80 westbound on-ramp to function as designed. The project consists of two new grade separation structures (Southgate Road Undercrossing and Hillcrest Road Overcrossing), and eleven retaining walls (including Caltrans standard retaining walls, soldier pile and lagging walls, sub-horizontal ground anchor walls, and MSE wall) to accommodate realignment and a new bicycle/pedestrian path. The South Bridge Head Foundation was constructed as part of the project. The main design objective is to minimize the impact to the new east span of the San Francisco – Oakland Bay Bridge (SFOBB). Recommendations considered interaction with the existing SFOBB foundations. PARIKH’s scope of work includes field explorations, geophysical survey (televiewer), laboratory testing, engineering analyses, and preparation of Foundation Reports and a Geotechnical Design and Materials Report.  In addition to new data collected, PARIKH reviewed previous geotechnical reports and as-built plans. This project was awarded the 2024 Interchange Project of the Year by the California Transportation Foundation.