Earthquake-reducing Researches On High-rise Concrete Shearwall Residence With Base Isolation

Seismic resistance and reduction techniques are the most important contents in the field of disaster prevention and reduction. This paper is about the analysis of small high-rise isolated structure and it is a project of Shanxi Nature Science Foundation (20051053).The paper analyzes the basic conceptions of the high-rise concrete base isolated structure and its research and application at home and abroad, states the mathod of analysis on stucture with base isolation:the normative simplified method and time history method.Firstly, it calculates and analyzes a high-rise shear wall isolated building in Taiyuan city. Then, according to the finite element method, the calculation models of fixed and isolated structure are set up, and their dynamic responses are calculated. The paper offers the basic natural frequency and their corresponding space, analyzes their characteristics, and the differences of these two calculation models. It calculates the two models of this building under earthquake wave in horizontal and 3-directions respectively. The paper offers the maximal story shearing force, compared with the result of normative simplified method Judging from maximal story shearing force reaction, the architectural maximal story shearing force of isolated building is only 22% of fixed building. Therefore, the structure above rubber bearing could be lessened by one of fortification intensity. The paper also analyzes isolation layer displacement, acceleration response, component internal force and vertical pressure of rubber bearing etc, of two models under frequently and rarely occurred earthquake load Judging from the story displacement of isolated structure, the displacement is much smaller than the limit value under rarely occurred earthquake loading, the upper part of structure is almost in elasticity state. According to the acceleration response of structure, the response of isolated structure under horizontal earthquake wave is much smaller than that of fixed structure.The following conclusion could be got from the contrastive reaction between isolated structure and fixed structure under the motivation of three dimensional earthquake wave: the isolated structure can not reduce the function of vertical earthquake wave.This paper also analyzes the energy of seismic response. The energy analysis showes that in the seismic response of isolated structure the isolated device can absorb the input energy efficiently. The isolation layer can absorb 80% of total earthquake energy under 3 dimensional earthquakes. The isolation layer blockes the upward transmission of earthquake energy. The upper part of structure only has the petty relative movement and deformation.