Seismic Damage Analysis Of Soil Structure Interaction System Under The Action Of Main Aftershock Sequence

China is one of the countries that most severely affected by earthquake disaster in the world.Principal earthquake is often accompanied by a series of strong aftershock.Strong aftershocks will further aggravate the cumulative damage of buildings,and even lead to collapse.Earthquakes not only cause serious economic losses in our country,but also pose a huge threat to the lives of our citizens.Therefore,this paper takes reinforced concrete frame structures of different heights as the research object considering the effects of foundation soil.Acorresponding Soil-Structure Interaction(SSI)system model was established based on Open Sees software platform,and seismic damage analysis of structures under main aftershock sequence earthquakes is carried out.The main contents of this paper are as follows:1.Taking reinforced concrete frame structures as the research object,RC frame structure model is established based on finite element software Open Sees.Combined with the soil model based on planar four-node element,the models of soil-structure interaction system considering different structural heights are obtained.At the same time,using the wave selection method based on the target response spectrum,only considering the fitting of the main shock response spectrum and the target response spectrum,10 real ground motions are selected from the PEER database,and 10 groups of main and aftershock sequence ground motions are constructed by random method.2.Based on the dynamic time history analysis method,the seismic response of soil structure interaction systems that with or without aftershocks is analyzed to study the impact of aftershocks on soil-structure interaction systems.Then,the main aftershock sequence ground motion is taken as input ground motion,The seismic response of the consolidated structure and the structure considering SSI effect were analyzed respectively.When studying the effects of aftershocks and soil structure interaction on the seismic response of structures,three frame structures with different story heights are taken as research objects.3.Based on the above research,seismic damage analysis of structures with different height and is further carried out.In the same way,that whether soil structure interaction is considered is also a variable during the seismic damage analysis.Select three representative damage models for local damage analysis of the structure,and then use the weighted combination method proposed by Park-Ang to calculate the damage index of global structure.