公里网格的强震动时程快速产出与共享——以2025年1月7日西藏定日M_(S)6.8地震为例  

Rapid generation and sharing of kilometer-grid strong motion time histories:A case study of the M S6.8 Dingri,Xizang earthquake on January 7,2025

作　　者：任叶飞[1,2] 王宏伟 刁红旗[1,2] 刘也 强生银 周宝峰 温瑞智 REN Yefei;WANG Hongwei;DIAO Hongqi;LIU Ye;QIANG Shengyin;ZHOU Baofeng;WEN Ruizhi(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所地震工程与工程振动重点实验室,黑龙江哈尔滨150080 [2]地震灾害防治应急管理部重点实验室,黑龙江哈尔滨150080

出　　处：《地震工程与工程振动》2025年第1期1-11,共11页Earthquake Engineering and Engineering Dynamics

基　　金：黑龙江省自然科学基金杰出青年项目(JQ2023E002);国家自然科学基金项目(U2239252,52478567)。

摘　　要：针对当前强震动观测网络尚不能给出覆盖震中近场所有区域的地震动输入记录,建立了公里网格的强震动时程快速产出工作的技术框架。以2025年1月7日西藏定日M S6.8地震为例,阐述了各技术环节的详细过程,开展了震源破裂过程反演、区域宏观场地条件估计和强震动时程模拟等工作。结果表明:①此次地震释放地震矩达4.7×10^(19) N·m,对应矩震级为7.05;断层滑动以正断层为主并带有少量的左旋走滑分量,最大滑动位移超过了3 m;破裂持续了20多秒,以向北方向破裂传播为主,可能会引起潜在的破裂方向性效应;②给出了30弧秒分辨率的V_(S30)分布图和工程场地分类图,震中附近区域场地以Ⅰ类和Ⅱ类为主,东南方向较大区域的V_(S30)介于260~510 m/s;③给出了近场区域(27°30′N~30°00′N、86°18′E~88°36′E)内14996个虚拟观测点的模拟三分量加速度时程,并由实际观测记录验证了模拟结果的准确性;最大水平向峰值地面加速度(peak ground acceleration,PGA)可达1.0 g,0.4、0.2 g等值线近似与Ⅸ、Ⅷ度等震线重合,0.10、0.05 g等值线围合区域略小于Ⅶ、Ⅵ度区范围。研究工作和成果可以为震中区域各类承灾体的损伤判别、灾害评估和韧性评估等工作提供合理的地震动输入。In response to the current inability of the strong-motion observation network to provide seismic input records covering all areas of the epicenter vicinity,a technical framework for the rapid generation of kilometer-grid strong motion time histories has been established.Taking the M S6.8 earthquake in Dingri,Xizang on January 7,2025,as an example,the detailed processes of each technical procedure are described,and work on the inversion of the source rupture process,estimation of regional site conditions,and simulation of strong motion time histories has been carried out.The following results are obtained.The earthquake released a seismic moment of 4.7×10^(19) N·m,corresponding to a moment magnitude of 7.05.The fault slip is predominantly normal with a small amount of left-lateral strike-slip component,and the maximum slip displacement exceeded 3 meters.The rupture lasted for more than 20 seconds,mainly propagating in the northward direction,which may cause potential directivity effects.A V_(S30) distribution map and engineering site classification map with a resolution of 30 arcseconds are provided,and the sites in the vicinity of epicenter area are mainly classified as ClassⅠand ClassⅡ,with V_(S30) values ranging from 260 m/s to 510 m/s in the majority of the southeast area.Simulated three-component acceleration time histories for 14996 virtual observation points in the near-field area(27°30′N~30°00′N、86°18′E~88°36′E)are provided,and the accuracy of the simulation results is verified by actual observation records.The maximum horizontal peak ground acceleration(PGA)can reach 1.0 g,and the 0.4 g and 0.2 g isolines approximately coincide with the IX andⅧisoseismals,while the 0.10 g and 0.05 g isolines enclose areas slightly smaller than theⅦandⅥisoseismal zones.This research work and its results can provide reasonable seismic input for the damage identification,disaster evaluation,and resilience assessment of various disaster-bearing bodies in the epicentral area.

关 键 词：强震动时程 定日地震 震源破裂过程 随机有限断层模拟 区域场地条件 

分 类 号：P315[天文地球—地震学]