Seismic Responses And Collapse Analysis Of RC Frame Under Far And Near Field Earthquake Considering Soil-foundation-structure Interaction

Interaction between soil, foundation and structure is an important factor that affect the seismic responses of the structure, but in general, the rigid foundation assumption is often used in the process of engineering design, however, the rationality of the rigid foundation assumption and it's security are questionable in many cases.Near-field earthquake is more destructive than far-field earthquake, so in this paper,the seismic response of the structure should be considered when the structures are under the action of near-field earthquake.(1) First in this paper, the theory of soil-structure interaction, the seismic response of the structure and the gravity second order effect are introduced, based on the development of the related theory and the application of corresponding analysis,the author present the necessity and feasibility of considering the soil-structure interaction and second order effect at the same time, especially when the structure is under the action of near-field earthquake.(2) A further research for the related theory of soil-structure interaction is studied,by comparision, the method considering soil-structure interaction form ATC40 is adopted in the paper and elastic-plastic time history analysis was carried out by using SAP2000. Then, the author interpret the relevant parameters.(3) A 10 layer reinforced concrete frame structure model is set up and get the seimic responses of the model under far-field earthquake by using the elastic-plastic time history analysis method. Seismic waves correspond to ?, ?, ?fields are adopted during the analysis and the seismic responses of the model in 7 degree frequent and rare earthquake considering SSI, second-order effect and the responses without considering them are comparied. Then, the influence of SSI and second-order on the collapse of structures are studied, mainly includes the distribution of plastic hinge and peak acceleration of earthquake when the structure collapse.(4) In order to study the effect of near-field earthquake on the seismic responses of the structure, seismic waves from the Chichi earthquake records is employed in the corresponding analysis, and compared with the results of the far-field earthquake.(5) In the paper, 12 seismic waves are downloaded from the Pacific Earthquake Engineering Research Center corresponding to C, D, E three kinds of fields, then elastic-plastic time history analysis is carried out according the different values ofPGV/PGA. The relashionship between the maximal interlayer displacements, the maximal top displacements,the base shear and the values of PGV/PGA are obtained when the structurea are under the action of frequent earthquake and rarely met earthquake. At last the analysis of the relationship between the collapse of the structures and the values of PGV/PGA is conducted, including the distribution of plastic hinges, damage location and seismic peak acceleration.