Seismic response of isolated continuous girder bridges based on soil-pile-bridges interaction

Taking the three spans isolated continuous girder bridges for the engineering background,Bouc-Wen restoring force model is adopted to simulate the nonlinear characteristics for LRB,multi-story liner system concentrated quality finite element analytic model considering SSI is established,and the time-history analysis procedure of the Wilson-θ step-by-step integration method used to solve the increment form nonlinear governing equation of motion considering SSI is programmed.We make a contrastive analysis based on before and after isolated bridges model of considering SSI and rigid foundation hypotheses by combining the procedure with calculation example.The results indicate that the considering SSI has larger value on the seismic response than the rigid foundation,but the seismic response value has no great difference between two models under pulse of typeⅠ and Ⅱ.The considering SSI has larger value on the seismic response than the rigid foundation under pulse of type Ⅲ,so the SSI can not be neglected in the isolated seismic design of bridges under pulse of type Ⅲ.The LRB isolated rate has insensitive to considering SSI or not,and LRB isolated rate has no great difference between two models under the same type of pulse,but the effect of LRB under pulse of typeⅠ and Ⅱis superior to effect of LRB under pulse of type Ⅲ.