Numerical analysis on interaction of frame-tube, raft foundation and ground

Based on real projects, a three-dimensional analysis model of 19 stories frame-tube superstructure, raft foundation and ground interaction system is established by the FEM software ANSYS to analyze the interaction characteristics under the vertical load. At the same time, the conventional analyse model is also established. The superstructure's and raft foundation's internal force, as well as foundation settlement, analyzed by the interaction model and the conventional model are compared. The influences of the variation of raft thickness and ground rigidity to the interaction system are investigated. The results show that obvious differences exist in the superstructure's and raft foundation's internal force and foundation settlement between the two models. The increase of raft thickness may reduce the differential settlement, but simultaneously increase the internal force of foundation. As the raft thickness increasing, its effects of reducing the additional force of superstructure become weaker and weaker. The effects of reducing the superstructure additional force by increasing ground rigidity are also limited.