2023年积石山M_(S)6.2地震诱发中川乡滑坡-泥流滑动过程与成因机理研究  

Sliding process and causative mechanism of the Zhongchuan landslide-mudflow disaster chain induced by the 2023 Jishishan M_(S)6.2 earthquake

作　　者：王辽 谢虹[1] 蒲小武 李智敏[2] 郭晓[1] 姚赟胜 WANG Liao;XIE Hong;PU Xiaowu;LI Zhimin;GUO Xiao;YAO Yunsheng(Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China;Qinghai Earthquake Agency,Xining 810001,Qinghai,China)

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]青海省地震局,青海西宁810001

出　　处：《地震工程学报》2024年第4期791-801,共11页China Earthquake Engineering Journal

基　　金：青海省基础研究计划项目(2022-ZJ-749);国家自然科学基金(42172227)。

摘　　要：北京时间2023年12月18日23时59分,甘肃省临夏回族自治州积石山县发生M_(S)6.2地震。该地震在青海省民和回族土族自治县中川乡引发了一次严重的滑坡-泥流灾害事件。通过详细的地质调查、低空摄影测量、现场工程地质测绘,以及含水率实验等综合手段,对该滑坡的基本特征、动态发展过程及成灾原因进行调查分析。研究结果显示,此次滑坡事件经历了分级和分块启动,呈现出渐退式的滑移特征。滑坡产生的原因如下:村民长期灌溉活动导致地下形成了饱水黄土层,在地震作用下这些饱水黄土层的孔隙水压力急剧增加,导致黄土液化,随后液化的饱水黄土层携带着上覆的非饱和土层迅速向沟道滑移;此外,滑坡体与地下冒水及干渠补给水混合,进一步促进了滑坡-泥流灾害的形成。研究区域附近多分布类似的灌溉区,因此未来地震发生时,对这类滑坡事件的预防与治理将成为重要的研究方向。On December 18,2023,an M_(S)6.2 earthquake occurred in Jishishan County,Gansu Province.This earthquake triggered a severe mudflow disaster in Zhongchuan Township,Minhe County,Qinghai Province.Based on the detailed on-site investigation,low-altitude photogrammetry,engineering geology mapping,and soil water content experiments,fundamental characteristics,dynamic development,as well as causative factors of the landslide disaster were investigated and analyzed.The results suggest that the landslide initiated in a phased and block-wise manner,demonstrating a progressively retreating slip pattern.The analysis suggests that the landslide was predominantly attributed to such composite factors:prolonged irrigation activities undertaken by local inhabitants culminated in the establishment of saturated loess layers beneath the surface;subsequent to the strong earthquake shaking,the pore water pressure within these saturated loess layers experienced a rapid escalation,inducing a state of liquefaction in the loess.This liquefied state prompted the swift descent of the saturated loess,bearing the overlying unsaturated soil layers,towards the gullies.Additionally,the landslide mass mixed with continuously and irrigation canals underground,further intensifying the formation of the landslide-debris flow disaster.The study area is surrounded by similar irrigation regions;therefore,the prevention and management of such landslides under future seismic conditions is very crucial.

关 键 词：积石山地震 黄土液化 滑坡-泥流灾害链 灌溉 滑动过程 

分 类 号：P642[天文地球—工程地质学]