Seismic Evaluation For Eccentrically Braced Steel Frame Under Near-field Earthquake With Velocity Pulse

The pulse wave form and long pulse period features of near-field earthquakeimpose higher requirement on intensity and deformation of structure. Taking the yielddisplacement as the design parameter, the yield point spectra (YPS), a new kind ofconstant ductility spectrum in terse form, is applicable to performance based seismicdesign and performance based seismic evaluation of structure.This paper selects5eccentrically braced steel frames designed as the currentstandards of China, and analyzes the features of the near-field and far-fieldearthquakes through several records of near-field earthquakes with velocity pulse.Meanwhile, this paper builds several earthquake waves under the moderate and strongearthquake to average YPS according to the construction site forms, and analyzes thestructure’s peak displacement, ductility and inter-story drift Indices under themoderate and strong earthquake by using the seismic performance evaluation basedon YPS. Finally, the analysis is contrasted with the dynamic time history analysisresult to evaluate the dependability of YPS in its application to near-field earthquake.The author also analyzes the effect velocity pulse of near-field earthquake upon thestructure by comparing the5examples’ responses under the far-field and near-fieldearthquake respectively.