Atkins was part of the design team for the new San Francisco-Oakland Bay Bridge. Atkins produced plans, specifications and estimates (PS&E) for the westbound approach structure.

The westbound approach structure spans from Oakland to the cable-stayed main span bridge that ends on Yerba Buena Island in San Francisco Bay. The cast-in-place concrete box girder approach structure consists of 12 spans divided into four frames. The superstructure geometry set by the architects included a continuously changing girder depth and soffit width and required a cantilevered deck overhang at one end. The changing superstructure geometry required sophisticated 3-D finite element analysis and complex modeling. The foundations of two frames are located underwater in the soft bay mud, requiring a special foundation design. The structure uses nine 1.8-meter-diameter driven steel piles per foundation.

To design this unique substructure, a non-linear time history analysis was performed on each foundation. The final structure meets the latest Caltrans seismic design criteria for bridges. In addition to structural design, Atkins also provided staged demolition plans for the existing approach structure. Atkins provides construction support during the construction phase.

• Structures
• Transportation design

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