Seismic design strategy of cable stayed bridges subjected to strong ground motions

Abstract

One typical medium span cable stayed bridge is selected to investigate its nonlinear plastic behavior and the effect on the seismic responses of other structural components. The nonlinear behavior is considered by different type of plastic elements based on the ratio of sectional capacity to linear seismic demand. A series of nonlinear time history analysis is then carried out under strong earthquake inputs with increasing intensities. The result shows that the yield sequence of the pylon columns and auxiliary piers may be different due to different ground motions and even under the same ground motion but with different intensities; meanwhile significant force redistribution is observed in columns owing to the yielding in plastic regions, however, the pylon still conserves certain plasticity margin according to the current design practice in China, which indicates the pylon limited ductility design might be an practical alternative subjected to strong ground motions.