场地相关设计反应谱特征周期的统计分析

Statistical Analysis on Corner Period of Site-Related Design Spectrum

利用近年来的工程场地地震安全性评价和地震小区划工作的成果 ,对上述工作中得到的场地相关反应谱的特征周期取值进行统计分析 ,并收集现有的强震记录计算其反应谱 ,将上述两个结果同两个版本的抗震设计规范 (GBJ11 89和GB5 0 0 11 2 0 0 1)中的规定进行比较。发现上述两本规范中的特征周期取值在不同程度上小于实际场地情况的统计平均值。其中 ,虽然GB5 0 0 11 2 0 0 1规范相对于GBJ11 89规范更加接近实际场地的情况 。

According to the results of site seismic hazard analysis completed in the last decade, 96 site-related design spectra are selected as samples in this study. The result shows that the value of the corner period (T_g) of the design spectrum in GBJ11-89 (China Seismic Building Code, issued in 1989) is less than the value obtained by site seismic hazard analysis. Same thing happens when we compare the design spectra of the Codes to the spectra according to the earthquake records. The value in current seismic design code, GBJ50011-2001, issued in 2001, is greater than that in GBJ11-89, but still less than the value got by site seismic hazard analysis. If we accept the value got by site seismic hazard analysis, we have a suspicion that 2/3 buildings built according to GBJ11-89 are not safe when an earthquake with 2% probabilities of exceedance in 50 years occurs.