Near-fault Seismic Analysis Of V-type Eccentrically Braced Steel Frames

According to the current code for seismic design of buildings (GB50011-2010)3.10.3, seismic action should multiply by1.25considering the ground motions effect ofnear-fault of5-10km ranges. While amplifying impaction of near-fault ground motions ondifferent forms and aseismic structures are not clear, the rationality research of near-faultseismic action amplification factor is needed.Three different stories V-type eccentrically braced steel frames (ten-story，fifteen-story，twenty-story) were designed based on the code（GB50011-2010）consideringthe amplification factor of1.25using SAP2000program and finite element models wereestablished by ABAQUS program.Ten significant velocity pulse ground motion recordswhich scaled to frequent and rare earthquake levels were considered for nonlinear dynamictime-history analysis.Results showed that both the maximum inter-story displacementangles (ISDA) were over code values respectively under frequent and rare earthquakes.The average value of base shear forces on frequent earthquake level was60percent largerthan the value calculated in the method of mode-superposition responsespectrum.Therefore,V-type eccentrically braced structure in near-fault designed accordingto the code(GB50011-2010) was unsafe and could not meet the basic principle of "nodamage under small and no collapse under strong earthquake".This paper suggest toestablish design response spectrum of near-fault to calculate near-field earthquake action.