湖北省域不同超越概率水平下地震动峰值加速度比例关系

The Proportional Relationship between Ground-Motion Peak Accelerations under Different Exceeding Probability Levels in Hubei Province

以第一次全国地震灾害风险普查工作成果为依据,计算并分析湖北省域不同超越概率水平下峰值加速度之间的比例关系及其空间分布特征。利用湖北省域宏观场地类别数据,计算得到湖北省域在多遇地震、基本地震和设防地震作用下场地峰值加速度比例关系:在0.05 g加速度分区中,湖北省域场地50 a超越概率63%与10%的峰值加速度比例(R_(63)/R_(10))均值为0.31,超越概率2%与10%的峰值加速度比例(R_(2)/R_(10))均值为1.81;在0.10 g加速度分区中,R_(63)/R_(10)均值为0.30,R_(2)/R_(10)均值为1.80;在0.15 g加速度分区中,R_(63)/R_(10)均值为0.17,R_(2)/R_(10)均值为1.98。在此基础上,与现行《建筑抗震设计规范》、《中国地震动参数区划图》等强制性国家标准中要求的比例进行对比分析,认为湖北省域采用《建筑抗震设计规范》中的取值对建筑物进行抗震作用计算,所考虑的地震作用是保守且安全的。同时,在湖北省高烈度区(如竹山、竹溪)开展地震危险性分析和地震灾害风险防治工作时,多遇地震下的地震动峰值加速度值宜按不低于基本地震动峰值加速度的1/3进行调整。该研究成果将有助于湖北省地震风险普查成果的推广和应用。

Based on the results of the first national earthquake disaster risk survey,we calculate and analyze the proportional relationship and spatial distribution characteristics of peak acceleration under different levels of exceedance probability in Hubei region.Using the macro site category data of Hubei Province,we calculate the proportion relationship of surface peak acceleration under frequent earthquakes,basic earthquakes,and fortified earthquakes.In the 0.05 g acceleration zone,the mean of the 50 years exceedance probability of 63%and 10%peak acceleration ratio(R_(63)/R_(10))for sites in Hubei Province is 0.31,and the mean of the 50 years exceedance probability of 2%and 10%peak acceleration ratio(R_(2)/R_(10))is 1.81;in the 0.10 g acceleration zone,the mean of R_(63)/R_(10)is 0.30,and the mean of R_(2)/R_(10)is 1.80;in the 0.15 g acceleration zone,the mean of R_(63)/R_(10)is 0.17,and the mean of R_(2)/R_(10)is 1.98.We comparatively analyze the proportion required by mandatory national standards such as current seismic design specifications for buildings and China’s seismic parameter zoning map.We infer that the seismic danger is reasonably safe in Hubei province,if rules of code for seismic design of building are followed.The peak ground motion acceleration value of frequent earthquakes should be adjusted to not less than 1/3 of the basic peak ground motion acceleration when conducting earthquake hazard analysis,earthquake disaster risk prevention and control work in high intensity areas,such as Zhushan and Zhuxi in Hubei province.The research results of this article will contribute to the promotion and application of earthquake risk survey results in Hubei province.