Research Of The Seismic Performance Evaluation Of RC Frame Structure With Considering The Effect Of SSI

With the rapid development of social economy, the wealth and population of the whole society become highly concentrated, as a result, the damages caused by earthquake disasters on human society may become more and more tremendous.Therefore, performance-based seismic design(PBSD) is the important development trend of seismic design nowdays,it firstly requires majority of researchers and engineers to have a more accurate acquirement of structural seismic response.Thus,regarding the upper structure and foundation as a interaction whole has a practical significance and necessity to design. This thesis will focuses on the research of dynamic characteristics of unsaturated sandy soil and the analysis method of Soil-Structure-Interaction(SSI):through a series of dynamic cyclic simple shear tests, it researches the influence rule of water content, strain amplitude and normal stress on the dynamic characteristics of soil.Also the thesis tries to imply the method of static elastoplastic Pushover and incremental dynamic analysis(IDA) method to analysis the SSI problems. Through experimental research and theoretical analysis, the thesis is expected to have a deep understanding of dynamic properties of sandy soil and the SSI problem. The main content is divided into five chapters as follows:(1) Overseas and domestic research status and level of SSI development are introduced. Based on previous experimental research and theoretical study, it puts forward the research content and expounds the necessity and method of the study.(2) Using WF system, it completes a series of cyclic simple shear tests of unsaturated soil with different water content and different normal stress under large strain. Then the thesis analyzes and summarizes the influence rule of moisture content and normal stress on the unsaturated soil characteristics (such as hysteresis curve, dynamic shear modulus and damping ratio), also provides necessary data support for the back analysis of modeling.(3) Based on the seismic performance evaluation method MPA of RC frame structure under horizontal seismic action, after considering soil-structure interaction, this thesis expounds the key problems need to be solved and the corresponding realization method:the simplification of SSI, the establishment of equations of system motion, the consideration of P-? effect under the gravity load, and the determination of nonlinear dynamic time history analysis of SDOF system.(4) For evaluation of frame structure seismic performance with considering SSI, there exist these following three methods:conventional Pushover method, the MPA method and nonlinear time history analysis method. Two styles of RC frame model, completely rigid foundation or considering SSI, are respectively located at II, III, IV site. To compare these seismic performance differences of RC frame structure between these two models under different site, including floor displacement, story drift and the distribution of plastic hinge, the thesis demonstrates that the necessity of considering SSI, and shows that MPA analysis method with the consideration of SSI is more feasible compared to other methods.(5) Respectively conduct a single earthquake record IDA analysis and multiple earthquake records IDA analysis both with considering SSI, as well as conduct Pushover method under different loading modes, in order to compare the difference and diversity among the static Pushover method including MPA and IDA method on evaluating seismic performance of RC frame structure.