2019年10月28日甘肃夏河5.7级地震强地面运动特征分析

Characteristics of Strong Ground Motion Records of the Xiahe,Gansu M5.7 Earthquake on October 28, 2019

摘要:

2019年10月28日甘肃省夏河县发生5.7级地震，中国数字强震动台网的18个专业台站在此次地震中触发。本文处理捕获的54条三分向加速度记录，给出近场台站的地震动参数，绘制了震中附近区域峰值加速度等值线图，其长轴呈WN-ES方向展布。将实际观测数据与几种常用地震动衰减关系对比，发现俞言祥^[1]短轴衰减预测模型能更好地反映此次地震的影响场。将振幅较大的62LBL、62BLX台的反应谱与我国抗震设计反应谱比较，采用最小二乘法拟合出不同震中距5个台站各周期谱加速度衰减特性，总结了此次地震的反应谱基本特征。运用H/V谱比法对4个典型台站进行场地地震反应分析，研究了局部场地条件对峰值加速度和峰值速度的影响过程。

Abstract:

A M5.7 earthquake occurred on October 28, 2019 in Xiahe County, Gansu Province. The main shock fully triggered 18 strong motion stations in the China Digital Strong Motion Network (CDSMN), for which we obtained and processed 54 records of three-component acceleration. In this paper, we identify the ground motion parameters of the near-field stations and present the peak acceleration contours near the epicenter. We also compare the actual observed values with several commonly used ground motion prediction equations. After comparing the acceleration response spectra of the 62LBL and 62BLX stations with the design response spectrum in China, we summarize the characteristics of the response spectrum of the M5.7 earthquake. To study the site effect on the peak acceleration and peak velocity, the H/V method was used to perform a seismic site effect analysis of four typical stations.