2018年2月12日河北永清4.3级地震强震动记录分析

2018年2月12日河北省廊坊市永清县发生4.3级地震，震中位于廊固凹陷内的河西务断裂附近，国家强震动台网中心获取74组强震动记录，本文对触发台站进行场地分类，结果显示大部分为Ⅰ类场地(51.35%)，其次为Ⅱ类场地(35.14%)和Ⅲ类场地(13.51%)。根据5个典型台站加速度时程记录及反应谱分析本次地震强震动特征，并对各台站峰值加速度反应谱与方位角和震中距的关系进行分析。采用克里格插值方法绘制地震仪器烈度分布图，由于台站分布不均，导致极震区附近烈度影响场计算缺值现象，本文通过拟合本次地震强震动记录得到该地区地震动衰减关系，在空白区域建立空间随机假设台站进行补点插值，解决了计算缺值问题，为缺少台站记录的震区提供准确快速制作烈度分布图的思路，为震害调查和地震应急救援提供重要依据。

Analysis of Strong Motion Records of Hebei Yongqing MS4.3 Earthquake on February12,2018

The strong motion records of Yongqing M4.3 earthquake occurring on February 12, 2018, were obtained by 77 strong motion stations of The China Strong Motion Network Center, and the seismic occurred near the Hexiwu fault of Langfang-Guan Depression. The paper classified the site of triggering stations, and the result show that most of them are Category I sites (51.35%), followed by Category Ⅱ sites (35.14%) and Category Ⅲ sites (13.51%). The Strong motion characteristics were analyzed based on the acceleration time duration and response spectrum of five typical stations, and the relation among the peak ground acceleration, epicentral distance and azimuth angles were discussed. The contour map of instrumental intensity was drawn using the Kreager interpolation method. Due to the uneven distribution of stations, the calculation results of the intensity influence field shows lack of numerical value near the epicentral area. In the paper, the ground motion attenuation relationship of the area is obtained by fitting the strong motion records, then establishes random hypothesis station in the space to make additional point interpolation, which solves the problem of the lack of the calculating numerical value of earthquake intensity influence field. The paper provides an idea of mapping accurate and rapid intensity distribution for the areas where earthquake will occur in the future and lack of station records, and provides an important basis for earthquake investigation and earthquake emergency rescue.