Analysis of Elastic-Plastic Seismic Response of a Low-Pylon Cable-Stayed Bridge under a Rare Earthquake

In order to research the feature of elastic-plastic response of low-pylon cable-stayed bridge under rare earthquake, a Midas model for elastic-plastic analysis was set up based on the theory of nonlinear time-history analysis and the definition of beam-column element model with Clough hysteretic behavior. In this model, a low-pylon cable-stayed bridge with span arrangement 144+288+144m was taking as an engineering background. Three sets of seismic waves accorded with site characteristic of bridge site were selected, and the elastic-plastic seismic responses of this bridge under rare earthquake were solved. The results show that only longitudinal displacement of double thin-wall piers yield and the piers generate unrecoverable residual deformation when entering into elastic-plastic state; Due to the elastic-plastic seismic response and the ductility seismic norm of bridge are related to the spectral characteristic of seismic wave, just checking the effects caused by only one set of seismic wave will not guarantee the security of ductility seismic design of bridge.