Analysis of the influence of near-field ground motion on the seismic response of RC frame structure in China
Near-field earthquakes often contain rich pulse components,and the impact effects generated in a short period of time will cause serious damage to building structures in the near-field area.Due to reinforced concrete(RC)frame structure widely used in urban areas in China,the influence of near-site earthquake on seismic response of frame structures in China should be studied.Based on the recent M7.8 earthquake in Turkey with relatively complete records,two near-field pulse-type and two non-pulse-type ground motions are selected as input.The shape features of acceleration response spectrum of4 ground motions are compared.The finite element models of RC frame structure with three different periods for respective 4,7 and 10 stories were designed and established,and the accuracy of the model was verified by the existing test results.The nonlinear dynamic time history analysis method is used to comprehensively analyze the influence of these two types of ground motions on the seismic response of frame structures by comparing the seismic acceleration response spectrum,the inter-story displacement angle of the structure,the energy consumption of the structure,and the utilization rate of the beam and column members.The effects of these two types of ground motions on the seismic response of frame structures are analyzed from the whole structure to the component level.The results show that the selected acceleration response spectrum of pulse-type ground motion has a long platform and obvious bimodal characteristics,while the acceleration response spectrum of non-pulse-type ground motion has obvious unimodal characteristics.Under the action of these two types of ground motion,the response of whole structure and beam/column of short-period structure are positively correlated with the value of seismic acceleration response spectrum.For medium and long-period structures,the acceleration response spectrum will be small and the structural response with the damage of beam/column will be large under the action of pulse-type ground motion,and the pulse-type ground motion will cause greater damage to the long-period structure.Therefore,the pulse effect of near-field ground motion should be fully considered in the seismic design of such structures.
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维普
