| Located in plateau mountain area,Yunnan is a province lacking construction land,whose mountainous area and half mountainous area accounts for for 94% of the total area of the province.Mountainous building is a architectural form closely integrated with mountain terrain and highly integrated with natural environment,and has significant advantages in developing slope(platform)land,due to small amount of digging and filling work,the application prospect of mountain building in Yunnan is very broad.However,Yunnan is also one of the provinces with the most serious earthquake disasters in China,and because of the innate vertical irregularity,the seismic capability of the mountain buildings is weak,in addition,the theoretical research on seismic design of mountain building structure lags behind engineering practice,therefore,there is an earthquake safety hazard in the construction of mountainous buildings in the seismic area.Under this background,the application of isolation technology in mountainous buildings is proposed in this thesis,forming a mountain isolated building,in order to improve the seismic capacity of mountain buildings.The work in this paper can be summarized as the follows:1.In chapter 1,according to the special requirements of the isolation technology and the traditional form of mountain buildings,mountain isolated buildings are classified into inclined plate form,step-terrace form,suspending form and middle layer form,and each particular problems of above 4 structure forms are proposed.In this paper,the typical isolated step-terrace structure form is taken as the research object.2.In chapter 2,firstly,the static finite element method is used to study the vertical stress distribution of rubber bearings in isolation layer under the combined action of horizontal earthquake and structural self weight,on this basis,taking the ultimate bearing capacity of rubber bearings under tension or compression as the critical condition for overturning failure of isolation structures,and introducing the difference of tension and pressure stiffness of the rubber bearing,then the theory of overturning failure mechanism of base isolation structure and isolated step-terrace structure are studied,and the calculation formula of limit aspect ratio of base isolation structure as well as isolated step-terrace structure in cross slope direction and CIS slope direction is derived,and finally the mechanism of overturning failure of isolated step-terrace structure is revealed.3.In chapter 3,in the light of the defect of partial design method,an envelope design method is proposed which is applicable for isolated step-terrace structure design,and an isolated step-terrace concrete frame structure with 2 dropped-layers and 1 span in 8 degree of aseismatic design area is designed in envelope design method,furthermore the effectiveness of envelope design method is preliminarily proved by finite element numerical analysis.Finally a shaking table test model was produced in the shape of the isolated step-terrace concrete frame structure according to the 1:10 similarity ratio.4.In chapter 4,in order to investigate the aseismatic performance,a series of shaking table tests of isolated and aseismatic step-terrace model are carried out using selected seismic waves based on different seismic levels,and a finite element model is established which is compared with the table test model.The experiment not only proves that the seismic performance of the isolated step-terrace model is superior,but also proves the feasibility of the envelope design method,and the calculation formula of limit aspect ratio of isolated step-terrace structure in cross slope direction and CIS slope direction are proved to be right too.5.In chapter 5,focus on the characteristics of poor tensile property of rubber bearing,a guide rail type anti-tensile rubber bearing has been proposed,and the horizontal compression-shear test and vertical uniaxial tensile test are carried out on the common rubber bearing and the guide-rail tensile rubber bearing respectively by pseudo-static test,then with the help of ABAQUS finite element analysis platform,the finite element numerical simulation of single tensile device and guide rail type anti-tensile rubber bearing is carried out.Finally,based on the pseudo-static test and finite element analysis,the constitutive relationship of the guide-rail tensile rubber bearing is proposed,and an engineering example is given to verify that the guide-rail tensile rubber bearing can obviously improve the overturning resistance of isolation structure.At present,the research field of mountain isolated buildings at home and abroad is still a blank,and these studies in this thesis are conducive to improve the seismic performance of mountain buildings and alleviate the pressure of construction land,and also let people know about the overturning failure process of the isolated step-terrace structure,consequently the anti overturning capability of the isolated step-terrace structure can be correctly evaluated in the plan stage.At the same time,an effective tensile device is proposed to improve the anti overturning capability of the isolated step-terrace structure.These studies provide a basis and reference for the design of the isolated step-terrace structure. |
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