Earthquake Stresses in the San Francisco-Oakland Bay Bridge

The combination of deep piers and long spans, of various types and degrees of rigidity, in the San Francisco-Oakland Bay Bridge, resulted in unusual problems in the calculation of earthquake stresses. This paper describes the assumptions which were made, typical examples of stress analysis, and the provisions incorporated to resist seismic forces. It was found that an acceleration equivalent to 10% of gravity produced stresses in the superstructure of the same order as those arising from the assumed wind loads. In general, very little additional material was required to resist earthquake forces. In the following, use has been made of data, including vibration measurements on the structure, not available at the time of the actual design. To such extent, this paper may be considered a review of the design.