MPA Analysis Of RC Frame With In-elevation Irregular Masonry Infilled Walls Considering Site Effect

The traditional MPA method is based on the assumption of rigid foundat ion.When the soil-structure interaction(SSI)needs to be considered,the traditional MPA is no longer applicable.On the other hand,SSI effect and filling wall have a complex relationship with the seismic performance of building structures.Traditional building structures often ignore or neglect these two factors.However,in many cases,the neglect of the relationship between the two and the seismic performance of buildings leads to significant damage to buildings and endangers the safety of people's li ves and property.Therefore,considering the irregularity of infilled walls and SSI effect,this paper studies the seismic performance of RC frame structures.The main contents are as follows:Firstly,the research status of infilled walls in frame structures and the development history and research status of SSI effect are introduced,and the significance of research on infilled walls and SSI effect in frame structures is expounded.Second,pushover and MPA analysis methods are introduced.Based on the method of considering SSI effect proposed by ATC-40,the MPA analysis method considering SSI effect is deduced by the principle of periodic equivalence,and verified by the time history analysis method.The results show that the MPA analysis considering SSI is basically consistent with the time history analysis results.This method is feasible.Thirdly,a RC frame infilled wall model is established by Sap2000.By changing the layout of infilled wall and the stiffness ratio between stories,the seismic response of this kind of structure under different site and intensity of protection is studied by using MPA analysis method considering SSI effect.It is found that when the "weak layer" formed by irregular arrangement of infilled walls is at the bottom and SSI effect is taken into account,the deformation of the structure under earthquake mainly concentrates on the bottom layer,the energy dissipation capacity of the structure decreases,and with the softening of the site soil,the stiffness ratio between the layers whose displacement angle exceeds the limit decreases significantly,and the seismic performance of the structure decreases significantly.Finally,based on the SSI effect and the "weak layer" formed by vert ical irregularity of filling wall at the bottom,the treatment measures a re studied.It is found that under the condition of providing similar lateral stiffness,adding BRB treatment measures can better control structural deformation and protect the main structure.