Research Into Interaction Between Superstructure And Foundation Of A High-rise Building

The acceleration of city urbanization and growing shortage of land resources have promoted the emergence and development of high-rise buildings in our country. The traditional approach is to design the structure, foundation and ground-base isolated separately. Since the traditional method ignores the influence of interaction, the results of calculation and actual situation is inconsistent, and this unreasonable phenomenon is quite obvious in high-rise buildings.This paper based on actual high-rise building with three-tower and enlarge base, which locates in Xi’an. According to the basic principles and methods of analysis interaction, this paper adopt viscoelastic artificial boundary method to simulate absorption of scattered wave generated by generalized structure, the piles-soil composite part of group piles foundation is equivalent to transversely isotropic body by equivalent complex model, and determined the relevant calculation parameters combine with engineering geological data. And then, established the corresponding calculation models separately with the finite element software Midas/Gen, and researched difference of structural seismic response and stress during the construction phase under the circumstances that consider the interaction or not. The work of this paper and main conclusions are as follows:(1) Made nonlinear static analysis with two directions to rigid foundation finite element model, and researched the development of the plastic hinge in the three-tower structure with enlarge base in this case. Identified the weaknesses of the structure and analyzed the internal force and deformation generated by disastrous seismic actions;(2) Analyzed the influence of SSI effect on the structural seismic response through comparing with the calculation results of the rigid foundation model, and obtaining the change rule of parameters such as base shear of structure and acceleration of the vertex;(3) Analyzed the seismic response of the weaknesses of structure, and obtain the change rule of weaknesses’ internal force which considered interaction;(4) Analyzed the stress state of the structure during construction,and to draw the conclusion that compared with the rigid foundation model, the internal force of the structure redistribute after take interaction into account, the internal force of side column is increase and of middle column is decrease.