远场长周期地震动选取及界定

Selection and definition on long-period ground motion of far-field

将东日本地震的97组地震动进行近远场地震动的划分,数据采取于强震动观测台网K-NET(Kyoshin Net);然后进行分析,用β谱曲线平滑段(2 s^10 s)的谱值,进行周期平方加权值βL的计算,以βL值是否大于0.4作为界定长周期地震动的标准。其中,采取βL>0.4的长周期地震动与0.2≤βL≤0.4中长期地震动作为样本进行研究。

97 groups of earthquakes in Eastern Japanese Earthquake are divided into near and far fields. The data are taken from Kyoshin Net(K-NET). Using the(2 s ~ 10 s) spectrum value of β,to calculate the periodic squared weighted value of βL,whether the value of βLis greater than 0. 4 is used as a criterion to define long-period ground motion. Among them,long-period earthquakes with βL> 0. 4 and long-term earthquakes with 0. 2≤βL≤0. 4 are taken as samples for research.