2023年甘肃积石山6.2级地震中川乡液化流滑灾害调查及诱因初析  

Preliminary analysis for the triggering of soil flowslide that occurred in Zhongchuan Town following the 2023 Jishishan M_(S)6.2 earthquake in Gansu Province

作　　者：陈龙伟[1,2] 汪云龙 袁晓铭[1,2] 李兆焱 王永志[1,2] 聂桂波 张昊宇[1,2] CHEN Longwei;WANG Yunlong;YUAN Xiaoming;LI Zhaoyan;WANG Yongzhi;NIE Guibo;ZHANG Haoyu(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》2024年第1期187-193,共7页Earthquake Engineering and Engineering Dynamics

基　　金：中国地震局工程力学研究所基本科研业务费专项资助项目(2021EEEVL0104)。

摘　　要：2023年12月18日甘肃省临夏州积石山县发生了6.2级地震,地震导致青海省民和县中川乡金田村和草滩村发生特殊的流滑灾害,其规模之大、灾害之重在国内外实不多见。通过实地考察,得出了地震土壤液化是此次流滑灾害诱因的结论,且此次灾害是近70 a以来首次具有现场实证性质的液化流滑型地震灾害。调查分析结果表明:流滑区上游滑源区地下土壤液化触发了流滑,中游流通区特殊的水文地质条件加剧了流滑的发展;土壤液化潜在多区、多源特性,即中游流通区存在疑似液化区;流滑区地震动强度较大,初步估计地震动峰值加速度值为0.4(±0.1)g。调查分析结果可为认识此次液化流滑灾害提供科学依据。On Dec.18th,2023,a magnitude 6.2 earthquake hit Jishishan Town of Linxia City in Gansu Province,and caused an unusual mud sliding disaster in Jintian Village and Caotan Village of Zhongchuan Town in Qinghai Province.The mud flowslide resulted in catastrophic consequences as casualties and demolishing and burying of residential houses.Such large mud sliding phenomenon has not been frequently reported in historical earthquakes.Through field investigation,it is confirmed that the underlain soil liquefied and triggered the disastrous phenomenon which has already been termed liquefaction-induced flowslide.Nevertheless,the massive liquefaction-induced flowslide is the first time been reported and verified by field evidence in recent 70 years.The investigation and analytical results demonstrate that the underlain soil layer in the upstream area liquefied,triggering instability and catastrophic flowslide,and the soil and water conditions in the flowing channel potentially accelerated the sliding.It is deduced that liquefaction possibly occurred in many a place,that is,the sliding channel was suspected of liquefying in various spots.The ground shaking intensity in the sliding area maintained relatively high,and that the peak ground-motion acceleration was estimated around 0.4(±0.1)g.The findings and investigation results are useful to help understanding the mechanism and process of the uncommon flowslide disaster.

关 键 词：积石山地震 土壤液化 诱因 现场调查 流滑灾害 

分 类 号：P315.9[天文地球—地震学]