舟曲江顶崖滑坡变形模式及发展趋势  

The deformation mode and development trend of the Jiangdingya landslide

作　　者：窦晓东 王信 李松 DOU Xiao-dong;WANG Xin;LI Song(Geological Environment Monitoring Institute of Gansu Province,Lanzhou 730050,China;Gansu Hydrogeological Engineering Geological Survey Institute Co.,Ltd.,Lanzhou 730020,China)

机构地区：[1]甘肃省地质环境监测院,兰州730050 [2]甘肃水文地质工程地质勘察院有限责任公司,兰州730020

出　　处：《兰州大学学报（自然科学版）》2024年第3期333-342,共10页Journal of Lanzhou University(Natural Sciences)

基　　金：中央引导地方科技发展资金项目(23ZYQA0326)。

摘　　要：以舟曲县江顶崖滑坡为依托,采用现场野外调查、工程地质钻孔勘探,全球导航卫星系统位移监测、无人机多期影像对比、变形历史对比、 Massflow数值模拟等方法获取滑坡变形的基本特征,分析滑坡复活机制、变形模式,再现其发展趋势及破坏范围.结果表明,江顶崖滑坡主要由降雨、江水冲刷诱发,降雨入渗在滑带处形成饱水带,软化、浸润滑面,导致滑带炭质板岩抗剪强度持续降低;江水冲蚀导致滑坡前缘失去支撑,最终诱发滑坡失稳;江顶崖滑坡拉裂滑动后后壁及侧壁出现“环状”灰黑色炭质板岩,中部形成洼地及平台,中前部出现多条鼓胀拉裂缝及剪切裂缝,前部形成多条放射状裂缝,滑体挤压白龙江河道,导致河道局部宽度不足5 m;江顶崖滑坡前部滑体滑动导致后部滑体失去支撑,加上后部滑体重力作用,导致局部复活,变形模式为前部牵引-后部推移的复合式破坏;数值模拟发现在不利工况下,滑坡堆积体将堵塞白龙江,形成18 m厚的堰塞体,并在滑坡上游形成6.6 km的回水淹没区,对上游南峪村、虎家崖村、安子坪村等村庄构成严重威胁,潜在危害大.Based on the Jiangdingya landslide in Zhouqu County,the basic characteristics of landslide deformation were obtained by means of field investigation,engineering geological drilling exploration,global navigation satellite system displacement monitoring,multi-stage image comparison of unmanned aerial vehicle,and comparative analysis of deformation history and a numerical simulation of mass flow.The reactivation mechanism and deformation mode of the landslide were analyzed,and its development trend and damage range reproduced.The research showed that the Jiangdingya landslide was mainly induced by rainfall,whose infiltration formed a saturated zone at the sliding zone,softening and invading the lubricating surface,and resulting in a continuous decrease of the shear strength of the carbonaceous slate in the sliding zone and inducing landslide instability.The "annular" gray-black carbonaceous slate appeared on the back wall and side wall of the landslide after cracking and sliding,depressions and platforms were formed in the middle,multiple bulging and tensile cracks and shear cracks appeared in the middle and front,and multiple radial cracks were formed in the front.The sliding body squeezed the Bailong River channel,resulting in a local channel of less than 5 m;the sliding of the front body of the Jiangdingya landslide led to a loss of support of the rear sliding body,and the weight force of the rear sliding body led to a local resurrection.The deformation mode was a composite failure of the front traction-backward displacement.Through the numerical simulation,it was found that,under unfavorable conditions,the landslide accumulation body would block the Bailong River,forming an 18 m thick barrier body and a 6.6 km backwater submerged area in the upstream,which posed a serious threat to the upstream villages such as Nanyu,Hujiaya and Anziping,with a great potential harm.

关 键 词：变形模式 发展趋势 数值模拟 动力过程 江顶崖滑坡 

分 类 号：P642[天文地球—工程地质学]