汶川地震近场区转动分量统计分析

Statistical Analysis of Rotational Components in Wenchuan Earthquake Near field Region

摘要:

通过选取汶川地区I类、 Ⅱ类和Ⅲ类场地共25个台站的地震记录按照平动分量和转动分量的关系计算得到相应的摇摆分量和扭转分量，并进行了统计分析.根据选择的地震记录得出以下的结论：① 转动分量和平动分量的相关性很大；② 在平动分量峰值相同的条件下，场地越软摇摆分量越大；③ 扭转分量约为摇摆分量的一半；④ 转动分量的衰减较慢.

Abstract:

The seismic records of 25 stations at the sites of Class Ⅰ,Ⅱ and Ⅲ in Wenchuan were selected. Their tilt and torsional components were calculated and statistically analyzed according to the relationship between translation and rotational components. The results show that the correlation between translation and rotational components is robust; if the peaks of translation component are the same, the rocking component is larger in softer site; the torsional component is half of the translational component; the attenuation of rotational component is slow.