NUMERICAL APPRAISAL OF THE PERFORMANCE OF COMPOSITE FOUNDATION SYSTEM WITH PILES AND CUSHION

Due to potential of subsoil and reinforcement sufficiently developed, intensive study on durability and performance of composite foundation is of great significance. In this paper, elasto-plastic numerical computation is conducted by developing elasto-plastic FE model in plane stress state, together with adopting Mohr-Coulomb yield criterion to describe the elaso-plasticity of subsoil and Coulomb contact pair theory with penalty algorithm to simulate the discontinuous contact behavior of foundation and soil, as well as using infinite element in model boundary to avoid static boundary effect. Based on the elasto-plastic numerical model of composite foundation with piles and cushion used above, the characteristics of internal forces and deformation of composite foundation system including raft, cushion and piles are analyzed. Furthermore, the respective effect of raft foundation, cushion and piles on the durability and performance of whole composite foundation system is discussed. On the basis of computational results and theoretical analyses, several conclusion remarks are drawn, which can provide referable experience to some extent for related engineering practice and design.