Abstract: A simplified analytical approach is proposed to study the behavior of piled raft foundation with rigid raft subjected to coupled loads in layered soils. Based on the shear displacement method, using the transfer matrix, the pile-pile interaction under vertical load is analyzed. Adopting the modified subgrade modulus, the pile head-pile head interaction under horizontal load is analyzed through the finite difference method. Based on solutions for stress and displacement in layered elastic half space, the interactions between pile head and soil surface, soil surface and pile head, soil surface and soil surface subjected to coupled loads are taken into account to determine the flexibility matrix of the pile group-soil system. Then the load-settlement relationship of rigid piled raft foundations subjected to coupled loads, load and settlement of the piles along the depth are obtained. Comparison between the finite element results and the calculated results is carried out; and the feasibility of the present method for analyzing piled raft foundation and the superiority of the modified subgrade modulus are proved. The piled raft foundation with rigid raft subjected to coupled loads is analyzed. The calculating results indicate that the horizontal load will cause the pile raft foundation oblique.

Key words: layered soil, piled raft foundation, coupled loads, interaction