Numerical simulation of piled raft foundation of super-tall buildings crossing metro tunnels

Based on the design practice of the tall buildings crossing metro tunnels, a three-dimensional finite element of shear wall-piled raft-soil is proposed to investigate the deformation and internal forces of piled raft foundation. The effects of superstructure rigidity, storey-by-storey construction, span length of metro tunnels and crossing methods are analyzed. The results indicate that considering shear wall rigidity can significantly reduce the differential settlement and the bending moment of raft for high-rise buildings. After superstructure rigidity reaches a certain degree, the differential settlement and the bending moment of the raft per unit load increase slowly. This shows the effects of the superstructure rigidity are limited. With the increase of the span length of metro tunnels, the maximum settlement, the differential settlement and the bending moment of the raft increase slightly. The crossing method of raft diagonal which coincides with the center of metro tunnels has the least influence on the internal forces and the bending moment of the raft. The reaction of piles agrees with the measured data.