Dynamic And Static Interaction Theory Research Of Super High-rise Tube-in-Tube Structure

The interaction between basement and superstructure is a popular research subject in civil engineering. But there is few people considering the tube-in-tube structure which is more sensitive to internal force change caused by soil-structure interaction. By means of theoretical analysis, numerical simulation and field measurement, the theory of dynamic and static interaction of super high-rise tube-in-tube structure is systemic studied.(1) In order to study the interaction mechanism of super high-rise building, a comprehensive in-site measurement on the post-telecom building in Shaanxi province is carried out. The measurement include basement settlement, pile's pile-top resistant, resistant of soil among piles, internal force of raft, the carrying load rate between piles and raft, and the free vibration frequency of the structure. According to measurement results, the internal force distribution laws of tube-in-tube structure and raft basement participated soil-structure interaction are developed.(2) Based on substructure method, an internal force calculating method of basement, foundation and superstructure subjected to vertical load is developed. The layered thick raft model which can consider both the transverse deformation induced by shear stress and effect of the raft reinforce stiffness are developed. An elastic-plastic model based on Drucker—Prager yield criterion are developed for basement. The twi-iteration method suited for soil-pile interaction is developed. The method calculate the nonlinear soil-pile contact and whole structure respectively, so it can not only well consider the contact nonlinear relationship between soil and pile, but also reduce the DOF number of the model(3) A numerical simulation of post-telecom building subject to vertical load is carried. Comparing with results of numerical calculation and field measurement, the validity of calculating model is proved. According to analysis of calculation results of pile's pile-top resistant, some suggestions on distribution of piles are presented.(4) A FEM/BEM coupled method for dynamic elastic reaction of interaction system subjected to frequent earthquake is also developed. The whole structure is divided into near region modeled by FEM and far region modeled by sub-region particular solution BEM. A simplified model of soil-pile system is developed. The stiffness matrix, mass matrix and damping matrix of foundation and superstructure are also developed. The equivalent stiffness matrix and mass matrix of far region are symmetrized and coupled with near regions', as a result, the calculating equations of whole interaction system is built.(5) A numerical calculation on dynamic characteristics of post-telecom building is carried out. Through the comparison between the results of numerical calculation and field measurement, the validity of dynamic interaction calculation method has been proved. Simultaneously, by means of calculating the seismic reaction of the post-telecom building, the mechanism of basement, foundation and superstructure seismic interaction of tube-in-tube structure subjected to earthquake is studied.