Study On The Characteristics Of The Development Of Typical Accumulation Body And Potential Destabilizing Mechanism In Hegu Valley

Based on the investigation and evaluation of slope geological hazards in the southwestern deep-cut river valley,this paper investigates the typical slope geological disasters in the Maoxian-Shuiying section of the Lancang River,and identifies the characteristics,material composition,and structural characteristics of typical large-scale accumulations and unstable slopes.Based on the collection and analysis of existing data,the use of high-precision remote sensing interpretation,engineering geological mapping,geological disaster measurement and engineering geological exploration as the main means to identify the topography of the study area,geological structure,rock and soil engineering characteristics,slope structure Types of geological hazards such as geological background and engineering geological conditions;to identify the type,size,characteristics of geological disasters,comprehensive analysis of geological hazards,spatial and temporal distribution patterns and disaster mechanisms.Taking the typical landslide deposits in the Maoxian-Shuijiao section of the Minjiang River as the main research object,macro and micro views,research areas and typical cases,point-to-face organic research methods are proposed,and large-scale accumulations are studied based on the existing work basis.The instability mode and the mechanism of unstable deformation of the accumulation body,and explore the potential instability mode and movement characteristics of the slope,combined with numerical simulation methods to simulate the process of instability,thus providing theoretical and technical support for the prediction and early warning of large-scale slope instability.(1)Work Area The Maoxian-Shuifan section is an alpine-gorge area.The mountains are towering,the rivers are deep,the valleys are deep,and the surface is undulating.Under such complicated terrain conditions,it is easy to produce large-scale giant collapse and landslide accumulation bodies.It can be seen that the accumulation body and strong deformation body developed in the work area are controlled to some extent by the topography and morphology condition.In the study area,hard metamorphic rocks are the main lithologies developed in the collapse disasters,and the main stream from the main stream of Maoxian County to the section of Tumen Village is the main area of the collapse.Soft metamorphic rocks are the main lithology of landslides in the industrial area.The main stream distribution of landslide geologic hazards is from the Mianmen village to the Shuifang section in the Qianjiang county.Due to the long-term strong structural changes in the transition zone between the Lushan uplift and the Longmenshan Houshan fault zone,the crushing structural plane of the rock mass is well developed and it is prone to landslides and landslides.It can be seen that the accumulation bodies and strong deformation bodies developed in the work area are controlled to some extent by the geological structure conditions.(2)The arc-shaped landslide has amplifying effect in both the horizontal direction and the vertical direction when the speed of the landslide decreases.However,compared with the vertical speed,the amplification effect of the horizontal speed is more significant.The motion mode of the arc landslide under earthquake response is: First,there will be peak acceleration amplification-Increased amplitude forces the trailing edge of the landslide to pull quickly-Sliding along the sliding surface-The potential energy of the accumulation body itself and the sliding energy of the accumulation body to drive the slope body Continue to do long-distance movement,the accumulation body in the decline process also occurs disintegration of the body,sporadic block ejection and other phenomena.Its instability mode is vibration cracking-disintegration in the middle-slipping off.(3)The smooth(forward)landslides under heavy rainfall conditions: the beginning of the rainfall process-the infiltration of rainwater causes the internal shear stress of the soil to increase and cause the front and rear edges of the landslide to pull quickly-along the sliding surface.Sliding—The huge potential energy and kinetic energy drive the slope body to perform distance movement,with the block sliding down and the particles colliding and scraping.Its instability mode is tensile shear failure-overall decline-slip pile.