Research On The Basic Characteristics And Control Of Large Debris Flow

Shaanxi Province is located in the middle of China and is the leading economic construction of the five provinces in the northwest.However,in the mountainous regions of northern Shaanxi and southern Shaanxi,the terrain is highly variable and geological disasters have developed.Especially in some areas of northern Shaanxi,geological disasters frequently occur.As China's "13th Five-Year Plan" and the "Belt and Road Initiative" continue to advance,the process of urbanization is accelerating.In some mountainous areas,geological disasters have severely hindered such urbanization and threatened people's lives and property.The study of debris flow in the field of geological disasters is relatively rare,and most of them focus on their distribution,prediction,etc.The study of large-scale debris flow is lack of relevant data.In a series of large-scale debris flow research and engineering governance,understanding its basic characteristics is the premise of studying the characteristics of the above-mentioned movements,the formation mechanism,and forecasting.In this paper,a large-scale debris flow in Jinggou of Wubao County in northern Shaanxi Province was used as an example.Through extensive field surveys and explorations,the first-hand data obtained were collated.Combined with conventional geotechnical tests and other tests,the basic features of the wells and mudslides were comprehensively analyzed.Formation conditions,influencing factors,etc.,were proposed for engineering control measures for large-scale debris flows represented by wells and debris flows.The main results are summarized as follows:(1)Large-scale debris flow generally has some common characteristics,that is,the same characteristics.Jinggou debris flow is a typical large-scale debris flow,with the following characteristics:(1)The Jinggou Valley is undulating,with ravines,deep river valleys,and high average annual rainfall.Jinggou is a year-round stream gully,with low flow during dry season and a large increase in water volume during the rainy season;(2)The Jinggou debris flow is a viscous debris flow in the torrential gully.The debris flow is rich in resources,mainly from the abandoned slag near the middle reaches of the railway,the alluvial sediments in the channel,the slope alluvial deposits on the both sides of the channel,residual slope deposits,and the downstream The artificial waste in the channel consists of man-made spoils in the middle reaches of the railway which are the most important and direct source of mudslides;(3)The upper reaches of Jinggou Valley are wide,and the middle and lower reaches are narrow.The overall shape is ?V?.The longitudinal slope of the channel is larger,the intensity of heavy rainfall is greater,and the hydrodynamic conditions are better,making the well become an easy-to-grip landslide.(2)The conditions for the formation of Jinggou debrits are mainly topographic conditions,solid material conditions and forehead water conditions.The topography and landform conditions include valley morphology,valley slope and catchment area;solid material conditions include artificial debris,channel and slope alluvium,adverse geologic effects on both sides of the channel,and garbage of residents living in the downstream channel;water conditions are mainly atmospheric precipitation.(3)The formation mechanism of Jinggou debris flow is a comprehensive mechanism of the mechanisms of rainfall impact mechanism,strength attenuation mechanism,erosion cutting mechanism and dragging mechanism of the ditch bed.(4)According to the characteristics of the Jinggou debris flow,the basic characteristics and the eigenvalues,formation conditions,influencing factors and formation mechanism were systematically studied.The corresponding prevention and control methods were put forward: a comprehensive treatment plan based on stabilization of artificial slag and smooth drainage was adopted.It mainly includes five aspects: solid slag,blockage,drainage,channel cleaning and greening.(5)The characteristic period of the seismic response spectrum of the Jinggou debris flow treatment project site is 0.35 s,the peak acceleration of the ground motion is 0.1g,and the corresponding basic earthquake intensity is VI degree;the surface water and the foundation soil of the treatment engineering site are opposite to the concrete structure and the reinforced concrete structure.All steel bars are considered slightly corrosive.The gravel material resources around the treatment project site are relatively abundant and can be selected or purchased nearby.