基于统计数据的非基岩核电厂抗震设计谱研究

Study on Spectral Accelerations for Seismic Design of Nuclear Power Plants on Non-Bedrock Sites Based on Statistical Data

为获取更为准确的抗震设计谱,统计分析了美国NGA-West2数据库中2661条强震动加速度记录数据,研究了相关地震参数对地震动反应谱的中长周期的影响,并建立了基岩(Ⅰ类)与非基岩(Ⅱ类、Ⅲ类)场地上水平向归一化加速度反应谱。结果表明,地震动反应谱受场地条件和矩震级的影响十分显著,受震源距离参数的影响较弱;与RG1.60谱、GB50267-97谱相比,本文获得的地震动反应谱能够更加可靠地估计场地覆盖层特性以及矩震级对地震动反应谱的中长周期的影响。最后,本文确定了考虑场地条件与地震构造环境影响的抗震设计谱,可作为非基岩核电厂选址及抗震设计的地震动输入。

In order to obtain more accurate spectral accelerations for seismic design, 2661 strong-motion acceleration records in the Next Generation Attenuation(NGA) West2 database were statistically analyzed, the effects of earthquake parameters on the middle to long periods of the ground motion spectral accelerations were studied, and normalized horizontal spectral accelerations on bedrock(site classification I in the Chinese standard) and non-bedrock(site classification II and III in the Chinese standard) for seismic design were established. The results indicated that the spectral accelerations of the ground motion were significantly influenced by site conditions and earthquake moment magnitudes, meanwhile they were slightly influenced by distance parameters of the earthquake source. Comparing to the spectral accelerations for seismic design suggested in RG1.60 of USNRC and GB50267-97 in China, the spectral accelerations of the ground motion obtained in this paper could evaluate the effects of site surface geology characteristics and earthquake moment magnitudes on the middle to long periods of the ground motion more reliably. Finally, the spectral accelerations for seismic design considering the influences of site conditions and seismotectonic environments were established, which could be used as the ground motion inputs in the site selection and seismic design of nuclear power plants on non-bedrock sites.