摘要
本文分析了渤海海域地震构造环境及地震活动特征,总结了近年来对该地区潜在震源区划分的一些新认识,分析了地震危险性区划结果.在此基础上,引入地震危险性特征参数K对研究区进行地震危险性分区,通过不同场点的地震危险性曲线证明了地震环境造成的危险性差异,并以研究区内3个概率水准的地震动峰值加速度的比值统计证明了引入地震危险性分区的必要性.研究表明:(1)不同概率水准的地震动参数之间不存在固定的比例关系,受地震环境影响,地震危险性分区和地震动参数区划图结合使用可以更准确地反应地震危险性特征;(2)对于一般工程,根据地震动参数区划图所给的50年超越概率10%的地震动参数折算所得到的小震的地震作用不具有统一的概率水准,抗震设防目标的实现没有科学保证;海洋平台抗震设计中利用强度水平地震推算得到韧性水平地震作用也不具有统一的概率水准;(3)将地震危险性分区和地震动参数区划结合使用或编制统一抗倒塌水准的区划图是一般工程抗震设防的科学做法,对于海洋平台的抗震设防,宜明确韧性水平地震作用的概率水准.
This article carries out an comprehensive evaluation on the seismicity and seismotectonie environments of Bohai Sea, sums up the new viewpoints on the division of potential seismic source zone, calculates the seismic risk, and makes an analysis on the seismic ground motion zontation. On this basis, the shape parameter of seismic risk curve, that is K, is introduced to delineate the seismic risk zone. The differences of seismic risk caused by seismic activity environment are demonstrated by the seismic risk curves at different sites. The ratios of ground motion for 3 exceeding probabilities illustrate the necessity of seismic risk zonation. The results show that： （1） There exists no fixed proportion between the ground motion of different exceeding probabilities, and it is effected by regional seismic environment, the combination of seismic risk zonation and seismic ground motion parameter zonation is a proper and comprehensive representation of seismic risk. （2） For the general engineering, the small earthquake is deduced from the ground motion with a exceeding probability of 10% in 50 years on the seismic ground motion zonation map, and their exceeding probability in different region are inconsistent with each other, and the fortification goals have no scientific guarantee. The ground motion of ductility level for the offshore platform design deduced from that of strength level also has no consistent exceeding probabilities. （3） The combination of seismic risk zonation and seismic ground motion zonation or compiling the seismic zoning map against collapse is the scientific choice for the general engineering, and for the offshore platform, the explicit exceeding probability of ductility design earthquake should be determined.
出处
《地球物理学进展》
CSCD
北大核心
2012年第1期18-28,共11页
Progress in Geophysics
基金
财政部2007年公益性行业科研专项200708055
国家科技支撑计划课题(2006BAC13B02)联合资助
关键词
地震危险性
抗震设防
设防水准
设防参数
渤海
seismic risk, seismic fortification, probability of exceedance, design parameters of ground motion, Bohai
