Research On The Seismic Isolation Performance Of Masonry Buildings In Villages And Towns

The collapse and destruction of village buildings under the earthquake are important causes of casualties and economic property losses.How to improve the anti-seismic performance of village buildings is the main task of implementing the strategy of revitalizing and developing villages and towns and the new urbanization in China.Using base isolation technology to improve the seismic performance of the buildings in villages and towns has great practical significance and application prospects for ensuring the safety of the village buildings under the earthquake.In this paper,the seismic performance of masonry structure buildings in villages and towns with low cost simple laminated rubber bearings is studied The main research contents and conclusions are as follows:(1)The ABAQUS finite element software and its failure criterion are used to simulate the low cycle repeated loading test of masonry wall panel.The rationality of masonry wall panel model is verified by comparing the seismic performance indexes in the test results.Based on ABAQUS finite element software,the isolation bearing is simplified as a spring-damping model,and the pseudo dynamic experimental data of the isolation bearing are compared and analyzed to verify the rationality of the simplified spring-damping model.(2)The centralized mass model is used to establish analysis models of fixed base structures and base-isolated structures at different periods.The seismic records are scaled using five seismic record scaling methods,and time-history analysis is performed.By analyzing the coefficient of variation of the top acceleration peak of the structure,Seismic recording scaling methods for fixed foundation structures and isolated structures suitable for different periods were determined.(3)A three-dimensional finite element model of the structure is established using the ABAQUS finite element software,that is,a fixed foundation structure model and a base-isolated structure model.Modal analysis is used to verify the rationality of each model,and mode shape response spectrum analysis and comparative analysis are performed.The seismic performance of each model in the elastic phase.The results show that the maximum horizontal displacement of the base-isolated structure is mainly concentrated in the isolation layer,and the upper structure is in the state of overall translation.The base isolation system has good isolation effect(4)According to the site characteristics,fortification intensity and the principle of seismic wave selection and scaling,the dynamic time history analysis is carried out for the finite element model of the above two cases,and the representative nodes are selected to analyze the displacement,acceleration and base shear in the seismic response,so as to study the seismic performance of the base isolated structure.The results show that the fixed foundation structure model can meet the requirements of three levels of seismic fortification,which are "no damage in small earthquake,repairable in medium earthquake and no collapse in large earthquake".The fixed foundation structure model is in a serious failure state under the action of 8 degree rare earthquake,but the base isolation structure model is in a basically intact state under the action of 8 degree rare earthquake.This is that the isolation system increases the basic period of the structural model,absorbs the energy of seismic wave,and greatly reduces the seismic response of the superstructure.Base isolation can significantly improve the seismic performance of masonry buildings.