甘肃陇南泻流坡滑坡-碎屑流变形特征与成因机制

泻流坡滑坡位于武都区白龙江右岸滑坡聚集区,属典型滑坡-碎屑流灾害,2020年8—10月高位滑源区发生持续变形破坏,严重威胁坡脚居民生命财产安全。通过详细的地质调查,综合运用位移监测、无人机航拍等手段,详细阐述了滑坡发育特征及变形破坏过程,并对其成因机制进行了分析。滑源区特殊的地形地貌、"碎石土+千枚岩"的二元结构、逆冲断裂的影响是滑坡形成的控制因素,多次地震为滑坡变形提供了结构基础,降雨入渗造成滑带软化、滑体自重增大等导致滑坡变形破坏。变形区主要为滑源区左侧中下部和右侧次级滑坡,经历两次加速变形过程,位移监测曲线呈阶跃型,属蠕滑-拉裂型推移式滑坡。滑坡处于蠕滑状态,亟须开展综合工程治理。

Deformation Characteristics and Formation Mechanism of Xieliupo Landslide-Debris Flow in Longnan, Gansu

A typical landslide-debris flow disaster, Xieliupo landslide is located in the landslide accumulation area on the right bank of Bailongjiang River in Wudu. From August to October 2020, the high-level sliding source area continued to deformation, which seriously threatened the life and property safety of the residents. On the basis of detailed field investigation, deformation monitoring and UAV, the deformation process and the formation mechanism are analyzed. The special topography, the binary structure of gravel soil and phyllite and the influence of thrust fault are the controlling factors for the formation of landslide, and earthquakes have occurred provide the structural foundation. Rainfall infiltration leads to the softening of the slide zone and the increase of the weight, which leads to landslide deformation and failure. The deformation area mainly consists of the middle and lower part on the left side and the secondary landslide on the right side of the sliding source area, which has experienced two accelerated deformation processes, therefor, the displacement monitoring curve is step-like. The geomechanical model of the landslide is creep-cracking. The landslide is in a state of creep slide, it is urgent to carry out comprehensive engineering control.