Causes And Classificaation Of High-level Collapse Clastic Flow

This paper analyzes,summarizes and organizes the relevant data of 103 actual cases of high-lever high-speed remote collapse landslide debris flow.Combined with field investigation and literature review,the formation conditions and causes of high-speed high-speed remote collapse landslide debris flow are obtained.Relevant classification of various characteristics of debris flow and disaster patterns.The collected and collected feature parameters are processed and analyzed by origin and spss,and the empirical formula of the debris flow area and horizontal slip distance is derived.The main research results are as follows:(1)High-lever high-speed long-distance collapse landslide debris flow geological disasters mainly include two major factors: First,the intrinsic factors such as topography(slope height,slope angle,geomorphology),geological structure,stratum lithology,rock mass structure.The second is the result of external factors such as weathering unloading,precipitation(rainfall,snowmelt and groundwater),earthquakes,human activities.The intrinsic factor is the basis for the formation of collapse and debris flow,the external factor is to induce and accelerate the development of the collapse and debris flow by changing the intrinsic characteristics of the slope rock and soil,ie,the intrinsic factors.Especially the slope height between 100 m and 500 m,46 occurred,accounting for 57%.(2)The relationship between topography and collapse and debris flow is analyzed,and the constraints of slope height,slope and geomorphology on the debris flow of collapse and landslide are revealed.It is found that the debris flow of the collapse landslide mainly occurs on the slope of slope height less than 1000 m,accounting for 87.5%.In terms of terrain slope,debris flow occurs mostly in slopes between 30° and 60°,accounting for 70%.Especially in the slope section of 30 ° ~ 45 °,38 occurred,accounting for 44%.The site selection of the project should avoid the terrain of the mid-alpine valley with steep slope and steep slope and the steep slope of the steep cliff,or reserve a certain distance as the buffer flow area of the debris flow,effectively reducing the impact damage of the debris flow.(3)The lithologic conditions of the debris flow stratum are analyzed and found that the combination of soft and hard phases or the upper and lower soft lithology is the main source of debris flow in the collapse landslide,Statistics also found that block and layered structures are the main structural types of collapse landslide debris flow.The influence of geological structures such as faults on the development characteristics of debris flow in collapse and landslide is analyzed,It is determined that geological structures such as faults are the main controlling factors for the development of debris flow,Further revealing the intrinsic relationship between geological structure and the development of collapse and debris flow.(4)Statistical analysis of collapsing and debris flow caused by different induced factors such as weathering,earthquake,precipitation and human activities,the main predisposing factors for the collapse of landslide debris flow are precipitation and earthquakes,The debris flow induced by precipitation and earthquake is 56 and 27,61% and 29% respectively.Analysis of different types of water factors,focus on the effects of surface water,groundwater and rainfall on debris flow.Among them,rainfall as the main inducing factor,accounting for up to 87%.(5)Basic characteristics and disaster patterns based on debris flow in collapse and landslide,divided into two types according to the composition of matter: rock and soil.rock collapse and debris flow is the most.Divided into small,medium,large,and very large collapse landslide debris flow by size,large and medium-sized collapse and debris flow accounted for a higher proportion.Divided into weathering,earthquake,rainfall and human engineering activities according to predisposing factors,among them,earthquake and rainfall induced.Classification of collapse and debris flow from the failure mode in the start-up phase.According to the motion pattern of debris flow,it can be summarized as excitation-start-acceleration-throwing-impact debris–scraping-stopping,excitation-start-acceleration-throwing-impact-chipification-scraping-stopping,excitation-start-crush-throw-impact debris-scraping-stopping.According to the disaster mode,it can be divided into impact and burial.(6)Study on characteristic parameters of debris-induced debris flow in earthquake-induced and rainfall-induced collapse,using origin to explore the relationship between the motion parameters related to debris flow in collapse and landslide,horizontal movement distance L and disaster area S and volume V,vertical motion distance H and slope slope gradient ?,linear relationship of equivalent friction coefficient f.Data standardization and correlation analysis of relevant motion parameters using dimensionless method and spss software,deriving the empirical formula for calculating the maximum horizontal distance L of collapsed landslide debris flow and the empirical formula for the disaster area S.