Influence Of Design Spectrum On Collapse Performance Of Anti-Seismic Structure

In china, the latest seismic design code, Code for seismic design of buildings(GB 50011-2001), was issued in 2001. But in the 1990's, all the buildings were built according to GBJ11-89 (Seismic Design Code 1989, China). In GBJ11-89, according to the results of sites seismic hazard analysis completed in past more ten years, the value of corner period Tg of the design spectrum is underestimated. This results in lacked for the anti-collapse capability when a destructive earthquake hit, while it was considered sufficiently according to GBJ11-89.In this paper, we first collect 63 results of sites seismic hazard analysis completed in past more ten years. Statistical evidence of the results shows that the value of corner period Tg of the design spectrum in GBJ11-89 is less than the value get by site seismic hazard analysis. If we accept the value get by site seismic hazard analysis as a true one, we have a suspicion that 2/3 buildings built according to GBJ11 -89 are not safe when a deconstructive earthquake occurs.So, we analyze the response of typical reinforcement moment frame six-story and ten-story buildings, which were constructed on the site type II with PGA 200 Gal or 300Gal (which is corresponding to intensity VIII in the intensity zoning map of China) and designed according to GBJ11-89. The IDARC 2D Version 5.0 is used to perform nonlinear time-history analysis. The artificial ground motions and the actually ground motions be seismic input to analyze the seismic response.The result shows that the buildings which are familiar to the our studied two buildings are not satisfied with the deformation limits in GBJ11-89. In the other words, the buildings max collapse when a deconstructive earthquake occurs. There are some important factors we do not take into account. In order to analysis the seismic response of building with more precision. we have many works to do in the future.