Seismic collapse analysis of high pier RC bridge crossing deep valley

Recently, many high pier RC bridges have been constructed crossing deep valleys at mountain areas in the western China, where the geotechnical condition is more complicated and the earthquake is more active. However, because the researches on seismic performance of such type of bridges are not sufficient and there is no seismic design specification, so far high pier bridges were designed referring to the seismic design code for ordinary RC bridges. To verify the seismic response performance and to predict the damage mechanism of a high pier bridge under earthquake, it is significant to analyze the earthquake response including its possible collapse pattern during strong earthquake. In this paper, a high pier RC at a typical mountain area was investigated as an example. The bridge is a multi-span continuous frame structure with high piers. Its deck consists of two parallel separate girders with curve. In the study, nonlinear seismic response analysis for the whole bridge was carried out using perfect elasto-plastic model. The process of plastic hinge development of the whole bridge and the damage mechanisms were studied. Collapse analysis on the whole bridge considering the collision of the two parallel bridge girders was simulated under strong earthquake. The methodology and results of the simulation in this paper is expected to be helpful for the seismic design and analysis of high pier RC bridge.