Study On Seismic Capacity Evaluation Method Considering Pounding Between Adjacent Buildings

Investigations into past several strong earthquakes have shown that structural collisions between adjacent buildings was one of the major reasons causing the severe damage or even collapse of buildings.Building structures that built before the new codes promulgated are often close to each other in the case of many buildings existing in our country,they may impact each other while responding to earthquake induced strong ground motion.Therefore,the seismic capacity evaluation and reinforcement of the existing buildings are very urgent.With the aim of studying on seismic capacity evaluation method considering pounding between adjacent buildings,this thesis mainly focuses on the following two aspects.Firstly,the thesis offers the conception of pounding spectrum of adjacent buildings,and analyzes its characteristics and influencing factors such as adjacent buildings mass,the width of seismic joint,PGA and the type of site.Secondly,the thesis summarizes the representative design spectrum of the collision with statistical analysis based on a lot of collision spectrum under strong earthquake records,compared with standard design spectrum and corrects demand spectrum.The thesis evaluates the seismic capacity of adjacent buildings with reference to individual buildings aseismic capacity evaluation methods.The main contents and conclusions are as follows:(1)Study on the pounding spectrum between adjacent buildingsThe research on pounding between buildings shows that: 1.on the one hand,the greater of the mass,the smaller structural acceleration response when the mass of adjacent structures are same;on the other hand,the mass of small structure is greatly influenced by the collision when the mass of adjacent structures are different;2.the impact of PGA and the width of seismic joint are similar,while PGA greater and the width of seismic joint smaller,the greater the structural acceleration response,and smaller on the contrary;3.four kinds of site conditions in the thesis are discussed in each kind of condition because the influence of site conditions varies according to the different working conditions.(2)The design spectrum considering the collision of adjacent buildingsThe thesis obtains the ratio of acceleration response spectrum between the collision is taken into account and not under the working condition based on the first part(1)work.And this ration is what we called amplification coefficient of acceleration response considering the collision of adjacent buildings.In order to obtain the design spectrum considering the collision of adjacent buildings,this thesis analyzes the law of the amplification coefficient with statistical method under a large number of ground motions.(3)Study on seismic capacity evaluation method considering pounding between adjacent buildingsAccording to the collision design spectrum offered in part(2),the thesis obtains the demand spectrum considering collision between adjacent buildings.Refer to the improved capacity spectrum method commonly used in individual buildings aseismic capability assessment,the thesis sets up two reinforced concrete frame models.The research on seismic capacity evaluation between buildings shows that: When the models suffer rare earthquake in correspond to the impact of its fortification intensity,they will have medium seismic capacity regardless of the collision;while considering the collision for adjacent buildings,the seismic capacity of structures is reduced and the lower level owing to the different specific conditions.