三峡库区三门洞滑坡复活机理及韧性变形研究  

Study on reactivation mechanism and ductile deformation of Sanmendong Landslide in Three Gorges Reservoir area

作　　者：张家旭 易庆林[1,2,3,4] 邓茂林[1,2,3,4] 安知利 彭云飞 雷玉 ZHANG Jiaxu;YI Qinglin;DENG Maolin;AN Zhili;PENG Yunfei;LEI Yu(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China;Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,China Three Gorges University,Yichang 443002,China;National Field Observation and Research Station of Landslides in Three Gorges Reservoir Area of Yangtze River,China Three Gorges University,Yichang 443002,China;Hubei Engineering Technology Research Center for Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China;Hubei Provincial Institute of Hydrogeology and Engineering Geological Survey Limited Company,Yichang 443002,China)

机构地区：[1]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002 [2]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [3]三峡大学湖北长江三峡滑坡国家野外科学观测研究站,湖北宜昌443002 [4]三峡大学湖北省防灾减灾工程技术研究中心,湖北宜昌443002 [5]湖北省水文地质工程地质勘察院有限公司,湖北宜昌443002

出　　处：《人民长江》2024年第4期160-168,共9页Yangtze River

基　　金：国家自然科学基金面上项目(42172303)。

摘　　要：三峡库区蓄水诱发大量库岸古滑坡复活变形,引入“韧性变形”概念可很好地解释古滑坡在相似影响因素下的差异性变形响应情况。以三峡库区三门洞滑坡为例,通过现场地质调查及17 a的监测数据,分析古滑坡复活过程中的变形特征及“韧性变形”机制。结果表明:①三峡库区三门洞滑坡为平缓堆积层古滑坡,自三峡水库蓄水后复活变形,前、中、后部变形主要为塌岸、拉张裂缝或坍滑和拉张剪切裂缝;②在库水位下降期间,滑坡的变形对库水位的快速下降响应敏感,库水在低水位运行和上升期间,滑坡变形主要诱发因素是降雨,尤其是连续性强降雨,可引发滑坡持续性变形;③滑坡发生“韧性变形”时,滑体内部经历一次密实过程,使得土体的密度增大,内聚力增强,提高了土体的抗剪能力,在一段时间内拥有抵抗下次变形的力量。研究成果可为三峡库区滑坡监测预警工作提供参考。The impoundment of the Three Gorges Reservoir triggers a large number of reactivated and deformed ancient landslides along the reservoir banks.The concept of“ductile deformation”is introduced to explain the differential deformation response of ancient landslides under similar influencing factors.Taking the Sanmendong Landslide in the Three Gorges Reservoir area as an example,we analyzes the deformation characteristics and the mechanism of“ductile deformation”during the reactivation process based on field geological investigations and 17 a of monitoring data.The research findings indicate that:①The Sanmendong Landslide is a gentle ancient sedimentary landslide that is reactivated and deformed after the impounding of the Three Gorges Reservoir.The main deformation features at the front,middle,and rear parts of the landslide are bank collapse,tensile cracks or slumping,and tensile-shear cracks respectively.②During the falling stage of reservoir water level,the landslide deformation is sensitive to rapid water level decrease.When the reservoir operates at low water levels and during the water rising periods,rainfall especially continuous heavy rainfall is the main triggering factor of landslide deformation,resulting in sustained deformation.③During the occurrence of“ductile deformation”,the internal part of the landslide undergoes a process of compaction,leading to increased soil density and enhanced cohesion,thus improving the shear resistance of the soil and providing the strength to resist subsequent deformations for a certain period.The research results can provide a reference for landslide monitoring and early warning in Three Gorges Reservoir area.

关 键 词：古滑坡 复活机理 韧性变形 三门洞滑坡 三峡库区 

分 类 号：P642.22[天文地球—工程地质学]