考虑不确定性的地震烈度与地震动参数关系研究

Study on the relationship between seismic intensity and ground motion parameters considering uncertainty

采用97次地震中800个强震动观测台站所获得的强震动记录及震后调查地震烈度作为基础数据,得到地震烈度与地震动参数PGA和PGV并不是一个确定性的对应关系,不确定性是一种客观存在,提出考虑不确定性的地震烈度与地震动参数关系研究。研究结果表明log PGA和log PGV的频数分布图在数据多的情况下符合正态分布,进而给出了考虑不确定性的地震烈度与地震动参数的概率公式,并给出了各个烈度下的参数拟合方法及结果。最后给出了新的考虑不确定性的地震烈度与地震动参数的概率公式在烈度快速评估中的应用。根据贝叶斯公式可以由某一场地的台站记录到的地震动参数来估计其地震烈度的可能性,即概率大小。根据某地区所有台站点的地震烈度期望与标准差,可得到整个地区的地震烈度评估期望图和标准差图,并给出了新疆呼图壁6.2级地震烈度评估的实例应用。

Based on both instrumental ground motion parameters and macroseismic intensity from 97 earthqukes which occurred during the period of 1933-2014 in the domestic and abroad,it is concluded that the relationships between the macroseismic intensity values and PGA,PGV is not a deterministic approaches. There is a great deal of uncertainty about the relationships between the macroseismic intensity values and instrumental ground motion parameters. Probabilistic relationship was developed to quantify these uncertainties. As the frequency distributions of log PGA and log PGV are consistent with the normal distribution,a new probabilistic formula of macroseismic intensity and ground motion parameters is established. Finally,the new probabilistic formulas are used for the rapid evaluation of the seismic intensity. According to the Bayesian formula,the possibility of seismic intensity can be esti-mated by the ground motion parameters recorded by a site station. According to the expectation and standard deviation of seismic intensity at the stations in a certain area,the expectation and standard deviation of the seismic intensity assessment of the whole area can be obtained. The application of the earthquake intensity assessment is used by Hutubi Ms6. 2 earthquake.