摘要
三峡库区吴家沟滑坡原先是处于稳定状态的松散堆积岸坡,在工程活动、暴雨、库水降落等综合作用下失稳破坏。以勘察、现场监测等手段查明岸坡地质结构特征,运用极限平衡分析法评价地形、暴雨、库水对岸坡稳定性的影响,探讨了滑坡的形成机制。结果表明,吴家沟滑坡主滑面为粉砂质粘土岩弃渣与基岩层的接触带,受库水长期浸泡软化,力学强度降低,为香溪河河岸人工堆积岸坡易滑地层;岸坡上进行的坡顶堆载、坡脚卸载等工程活动,使岸坡局部形成“上陡下缓”地形,为滑坡的形成和发展提供了临空地形条件;库水位降落到对岸坡最不利水位,与同时发生的暴雨共同诱发滑坡。研究成果可为后续库区工程建设提供借鉴。
The Wujiagou landslide in the Three Gorges reservoir area was originally a loosely colluvium bank slope in a stable state.However,after the transformation of human engineering activities,the bank slope slipped during heavy rain and reservoir water drawdowns.The geological characteristics and sliding depth are identified by means of survey,field monitoring,and limit equilibrium analysis approaches.The impact of the three environmental variables of the terrain,the rainstorm,and the reservoir water on the factor of safety of the landslide is quantitatively analyzed by the theoretical analysis.The formation mechanism of the landslide was discussed.The main sliding surface of the Wujiagou landslide is the contact zone between the silty claystone spoil and the bedrock layer.It becomes the slip plane under the long-term softening effect of reservoir water drawdowns.Engineering activities such as surcharging at the top of the slope and unloading at the toe of the slope have resulted in a“steep up and gentle down”topography of the bank slope.The activity provided space for the formation and development of the landslide.The torrential rain happened now when the reservoir water level dropped to the most unfavorable water level,and finally induced a landslide.The research results provide a reference for the subsequent construction of the reservoir area.
作者
王帅
郑宏伟
梁冠亭
WANG Shuai;ZHENG Hongwei;LIANG Guanting(Yangtze River Scientific ResearchInstitute,Wuhan 430000;Hubei Zixing Yangtze River Bridge Construction and Development Co.Ltd.,Yichang 443621;Wuhan Municipal Construction Group,Wuhan 430000)
出处
《土工基础》
2023年第1期104-108,共5页
Soil Engineering and Foundation
基金
国家自然科学基金(42002276,41877280)。
关键词
三峡库区
滑坡
松散堆积体
暴雨
库水降落
地形改造
Three Gorges Reservoir Area
Landslide
Loose Colluviums
Heavy Rain
Reservoir Drawdown
Terrain Modification
