3栋相邻高层建筑上部结构-基础-地基相互作用研究

Study on structure-foundation-soil interaction of three tall buildings

在同一场地地基上建设多栋高层建筑,应考虑建筑与地基之间的相互影响。利用数值计算方法模拟从基坑开挖到3栋建筑依次建立的整个过程,分析桩筏基础的变形和受力特性以及新建建筑与已建建筑的相互影响等。研究结果表明:已建建筑桩的轴力分布随新建建筑荷载的增加趋于均匀,而其最大值则逐渐减小;基坑开挖的卸荷作用使得基坑开挖面一定范围内应力有所减小;由于附加应力的扩散作用,使新建建筑的基础沉降最大值位置、桩的轴力最大值位置、筏板高应力区域均有向已有建筑物方向偏移的趋势。此外,基坑开挖后,已有建筑物的筏板沉降分布向基坑开挖方向有移动,并产生较明显的附加沉降,并且各种建筑荷载的相互叠加,最终会使基础周边的地面产生一定沉降。

Based on the principle of structure-foundation-soil interaction, a three-dimensional numerical analysis was carried out on a system consisting of three tall buildings at the same location, including the whole process from excavation of pit to the construction of superstructure in a certain order. The deformation and stresses of pile-raft foundation, and the interactions between the three buildings were discussed. Calculation results show that the influences between the buildings are obvious. The distribution of axial stresses in piles of existing building is more uniform with the additional loading from the new building. The maximum axial stresses of piles are decreased. During excavation unloading, the stress at the same location of the new buildings is reduced. Due to the diffusion of the additional stresses, the location of the maximum settlement of foundation, the maximum axial force of piles, and the region of high stress of raft board are relocated to the new building. After the excavation of the pits, the raft settlement of existing buildings moves to the pit excavation direction and exhibits obvious additional settlement. The settlement of the ground surface around tall buildings is also increased due to the accumulated stresses of three buildings.