季节冻土区黄土滑坡形成机理研究——以新疆伊犁加朗普特滑坡群为例  

Research on the formation mechanism of loess landslide in seasonally frozen ground region:a case study of Garangput landslide group

作　　者：魏学利 陈其鹏 焦友金 午洋泽 许瀚文 向翻 石兴武 WEI Xueli;CHEN Qipeng;JIAO Youjin;WU Yangze;XU Hanwen;XIANG Fan;SHI Xingwu(Chengdu University of Information Technology,Chengdu 610103,China;China Railway No.3 Engineering Group Co.,Ltd.,Taiyuan 030000,China)

机构地区：[1]成都信息工程大学,四川成都610103 [2]中铁三局集团有限公司,山西太原030000

出　　处：《冰川冻土》2024年第6期1871-1882,共12页Journal of Glaciology and Geocryology

基　　金：中铁三局集团有限公司科研项目(ZTSJ-SHGS-JSFW-2022-005);四川中央引导地方基金(22ZYZYTS0063);成都信息工程大学科研项目(KYTZ2022126)资助。

摘　　要：近年来,季节冻土区滑坡灾害的发生频率逐渐增加且危害加重,引起人们的广泛关注。相对于非季节冻土区,季节冻土区的积雪消融和土体冻融的物理过程是否对滑坡产生影响,有待进一步研究。2002年5月9日发生在中国天山伊犁地区的一个巨型黄土滑坡群(加郎普特滑坡群)为本研究提供了一个理想案例。本研究基于实地勘察、遥感影像判识、气象数据分析和黄土特征试验等方法,探究加朗普特滑坡群的形成过程,揭示其破坏模式和失稳机理。研究表明,加朗普特黄土滑坡群由3个滑坡构成,总堆积方量约1 735.5×104 m3,滑动过程断断续续持续了2天,其形成与发展是多级、多次的推移式滑动破坏过程。加朗普特滑坡群的发生是早期融雪和后期暴雨耦合触发的结果。春季气温异常升高驱动的积雪融水影响斜坡前期变形演化,极端暴雨是滑坡发生的激发因素。另外,特殊坡体结构和地层组合为黄土滑坡发生提供了物质结构基础。结合斜坡变形过程我们建立了考虑降水入渗和冻融循环作用的黄土斜坡变形破坏模式,并提出了黄土斜坡滑面静态液化和坡脚滑动液化的联合是诱发黄土滑坡发生的重要机理。随着气候变化驱动的异常升温事件增多,未来天山季节冻土区发生大型黄土滑坡的风险极高。本研究对认识融雪诱发黄土滑坡的形成机制提供新思路,对理解季节冻土区滑坡的早期预警和风险评估具有重要意义。In seasonally frozen ground region landslides are become a more common geological disaster,which has attracted widespread attention in the world.Whether the physical processes of snow ablation and soil freezing and thawing in seasonally frozen ground region,as opposed to the non-monsoon freezing zone,have an impact on landslides deserves further study.A giant loess landslide group(Galamput landslide group) occurred on May 9,2002 in the Ili region of China provides an ideal case study.By using field survey,remote sensing image identification,meteorological data analysis and loess characteristic test,we attempt to explore the formation process and failure mode,and further reveal the instability mechanism of Galamput landslide group.The results show that the Garamput loess landslide group is composed of three landslides with a total volume of approximately 17.355 million m3.The formation and development of the landslide group was a multi-stage and multiple sliding failure process.The Galamput landslide was the coupling triggering result of early snowmelt and post rainstorm.The snowmelt infiltration and soil freeze-thaw cycle in spring played an important role in the evolution process of slope deformation.The rapid infiltration of extreme rainstorm was the ultimate triggering factor of the landslide.In addition,special slope structures and stratigraphic combinations provide a material structural basis for the occurrence of loess landslides.Combined with the slope deformation process we established a deformation failure model for loess slopes considering the effects of precipitation infiltration and freeze-thaw cycles,and proposed that the combination of static liquefaction on the slip surface and sliding liquefaction at the foot of the slope is an important mechanism inducing the occurrence of loess landslides.In the future,the risk of large-scale landslides in the Ten-zan's seasonally frozen ground region is extremely high with climate warming.This study can provide a new perspective on the formation process and fai

关 键 词：黄土滑坡群 破坏机理 融雪 暴雨 季节冻土区 

分 类 号：P642.22[天文地球—工程地质学]