Substructure-finite element method for soil-foundation-structure interaction of CFST arch bridges

In order to study the soil-foundation-structure interaction of concrete filled steel tube(CFST) arch bridges, the theory of substructure is introduced and the substructure-finite element method is adopted. Taking the Nanning Yonghe Bridge for example, three models are developed, which the soil-foundation interaction is introduced in model 1, the interaction is analyzed using Finite Element Method (FEM) in model 2 and using substructure-finite element method in model 3. The vibration characteristics and seismic response of theses models are analyzed. The results show that the natural vibration frequencies of model considered soil-foundation-structure interaction are lower and the displacements and internal forces of seismic response are larger. The natural vibration frequencies and seismic response of the model of soil-foundation-structure interaction simulated using substructure-finite element method are similar to the model using finite element method.