Civil Engineering Association

Seismic Response of Precast Segmental Bridge Superstructures

While precast segmental bridge construction can help accelerate construction and reduce construction costs in congested urban environments and environmentally sensitive regions, the use of precast segmental bridges in seismic regions of the U.S. has been limited. A primary obstacle to their use is the concern regarding seismic response of segment joints. This report summarizes recent research that has shown that segment joints can sustain very large rotation opening up gaps in the superstructure without significant loss of strength. Using models of precast segmental bridges similar to the Otay River Bridge in San Diego County and the San Francisco-Oakland Bay Bridge Skyway as case studies, the study also investigates the response of segment joints using detailed finite element analyses. A suite of ten near field earthquake records are used for determining the median joint response and for quantifying the effect of vertical motion on the joint response.