Analysis of seismic response of the long-span through CFST arch bridge

In order to study the seismic response of the long-span through concrete filled steel tube (CFST) arch bridge, the finite element analysis software of ANSYS is applied to set up a modal according to a through CFST. The comparative study on seismic response analysis with the consideration of soil-pile-structure interaction by taking Tianjin seismic wave and EI Centro wave as the input waves, and then the paper analyses and discusses the dynamic characteristics of foundation consolidation and soil-pile-structure interaction and the influence of the upper structure. The results show that ➀most vibrations in the first 10 orders modal shape are in the transverse direction of the bridge which indicates that stiffness in longitudinal direction is larger than that in transverse direction, the soil-pile-structure interaction has certain influence on free vibration characteristics, but not obvious; ➁the section at arch springing of multiple arch and midspan is the most dangerous section; ➂compare with the foundation consolidation, the soil-pile-structure interaction can represent the effect of soil characteristics, and better reflects the structure of dynamic characteristics, extends the natural vibration period. The response of the internal force of each part of the structure has the tendency of decreasing.