Research On Practical Method And Technology Of Seismic Isolation For Rural Residential Buildings

The seismic performance of rural houses in China is generally poor.In previous strong earthquakes,houses in rural areas have suffered serious damage or even collapse,resulting in a large amount of casualties and economic losses.Therefore,it is of great practical significance to study the seismic performance of rural residential buildings.Structural seismic strengthening technology and seismic isolation technology are two main ways to improve the seismic performance of buildings.At present,the researches of seismic isolation technology for rural residential buildings are mainly concentrated in the direction of base isolation,while the researches of Geotechnical Seismic Isolation(GSI)direction are still few and lack of large-scale model-test work in laboratory or field.To reduce the risk of rural houses suffered from the earthquake disaster,based on the concept of GSI,two low-cost GSI systems are proposed for rural houses in earthquakeprone and cold areas in China.The isolation mechanism was analyzed theoretically and a large-scale shaking table test of the farming-residence model-base-geotechnical vibration isolation system-foundation was carried out.The shaking table model test and the prototype farm house were numerically simulated by using ABAQUS finite element software.Based on the above,proposals for the designment and construction of two geotechnical isolation systems for practical engineering applications were put forward preliminarily.The specific research work and achievements are as follows:1.Proposal and theoretical study of two kinds of GSI systemsBased on the concept of GSI technology,two low-cost GSI systems are proposed,i.e.based on Sand Cushion(GSI-SC)and based on Glass Bead-Sand Cushion(GSIGBSC).The simplified analysis model is established,and the isolation mechanism of the GSI is verified by an example.2.Shaking table test of two kinds of GSI systemsThe shaking table test scheme was designed.The large-scale shaking table test of the farming-residence model-base-geotechnical vibration isolation system-foundation was carried out by making 1/4 scale masonry structure models.The test phenomena and the acceleration response,displacement response,and strain response of the structural model were compared and analyzed in detail.The test results show that when a powerful earthquake happens,the isolation effect of the two kinds of GSI systems is good and the isolation effect of the two kinds of GSI systems is verified;as the increase of input acceleration amplitude,the isolation effect of GSI-SC isolation system and GSI-GBSC isolation system is more obvious,and the GSI-GBSC isolation system is better.3.Numerical simulation of shaking table test for two kinds of GSI systemsThe numerical simulation of the shaking table test was carried out by the finite element software ABAQUS,and the numerical simulation results of the shaking table test were contrastively analyzed with the experimental results.The results show that the numerical simulation results are in good agreement with the experimental results,which verifies the reliability of the finite element modeling method.4.Study on isolation effect and influencing factors of GSI systemThe finite element models of the prototype structure and site were created by using ABAQUS finite element software.The structural acceleration response,structural damage nephogram,displacement response and cumulative plastic deformation of soil were compared between the finite element models with and without isolation,showing that the GSI system has a good isolation effect.Through a large number of numerical simulations,the influence factors of the isolation effect of the GSI system were discussed.5.Based on the results of shaking table model test and numerical simulation analysis,the suggestions of applying two kinds of GSI systems for engineering and constructing practically were put forward.