Near-Field Seismic Analysis Of Chevron Braced Steel Frames

Since the long term velocity pulse effect, near-field ground motion requires a higherstructural strength and deformation. However, the designation of current code responsespectrum does not meet the requirements of near-field ground motions. Relating to CODEFOR SEISMIC DESIGN OF BUILDINGS (clause3.10.3), structures on both sides in theseismogenic fault within10km, ground motion parameters should be included in thenear-field impact; structures on both sides in the seismogenic fault within5km, earthquakeaction should multiply intensification coefficient1.5; out of5km, earthquake action shouldmultiply intensification coefficient which is not less than1.25. This provision does notconsider the changes in response spectra, only roughly synchronized magnified the spectralvalues of response spectrum on far-field ground motion’s fixed shape in order to improveearthquake action of near-field ground motion. There’s no basis in the clause andclarification. The source of intensification coefficient is not clear. In addition, littleliterature is on its safety and rationality.Strictly according to the standard design code and considering the impact of near-fieldeffect, the subject of this paper is the CBSF on both sides in the seismogenic fault from5km to10km. In the paper, earthquake action is multiplied with intensification coefficient1.25; Nonlinear time-history analysis is used to evaluate the reaction of CBSF undernear-field ground motion Analysis on the inner force and displacement time history ofenergy consumption component (brace). All these are in order to evaluate the rationality ofCODE FOR SEISMIC DESIGN OF BUILDINGS (clause3.10.3) and provide basis for thelate loading test and performance-based seismic design.