The Study On The Internal Forces In The Big Raft Of Multi-Tower Structure

Multi-tower structure with piled raft foundations is widely adopted nowadays by the new-built business office buildings. However, the design and computation of internal forces in the raft of this structure is based on approximation in the engineering field, not in accordance with the real situation. As a result, the design tends to be insecure or wasteful.Based on the design outcome, a simplified analysis model and computational method is adopted to make a FEM analysis of intemal forces in the raft of Shanghai Oasis Business Harbor by ANSYS, with the emphasis on the problems such as the rationality of the post-pouring settlement belt, the check of the reinforcement in the raft, the determination of the time to pour the post-pouring settlement belt, and the influence of the superstructure on the internal forces and settlement in the raft.The main computation and outcome are as follows:1. Based on the outcome of solo-buildings design, simplified computational method is applied to compute the settlement and internal forces of the raft in the architectural complex;2. Checking the setup of post-pouring settlement belt and the reinforcement in the raft of this project, it turns out that they are excessively safe in the part of the raft;3. The pouring time of post-pouring settlement belt in the raft of Shanghai Oasis Business Harbor is determined with this simplified computational method;4. Through the computation of solo-buildings with different types of superstructure, the influence range of superstructure rigidity on the settlement and internal forces in the raft is determined.At last, some reasonable conclusions and suggestions are put forward to the design of raft in similar real project.