Effects of Site Factors on the Performance of Rigid-Pile Composite Foundation in Tall Buildings

Values of site factors in numerical simulation can have profound effects on the calculation accuracy. In order to fully understand the performance of rigid-pile composite foundation in tall buildings, this article set up an overall FEA model of a 25-storey frame-tube structure by considering the interaction of superstructure, foundation and ground. Thereafter, a detailed parametric study was performed by changing values of different key site factors. These parameters include: Ground soil range, distance of neighboring buildings and deformation modulus of cushion. The results show that 1) Ground soil range has a great influence on the stress and settlement of raft, the effective influence range is 2-3 times of the raft dimension; 2) Influence of neighboring buildings on the stress and settlement of the raft can be neglected; 3) With the increase of cushion modulus, the raft stress increases while the settlement decreases, an optimal cushion modulus is recommended to be 20-40MPa.