Research On Start-up Mechanism And Control Countermeasure Of Slag-type Debris Flow In XuJiaGou Of Panzhihua

slag-type debris flow is a kind of main natural mountain mining area geological disasters,it is in the process of mining loose solid slag as the main source of debris flow,belongs to a kind of typical debris flow.Compared with normal natural debris flows,the slag type of debris flow is characterized by human nature,high volatility,high frequency,and high harmfulness.The continuous development of mines has caused serious geological environment problems such as mudslides,which are increasingly serious and hinder the sustainable development of mining and endanger the safety of people's property.This article takes the slag-type debris flow in XuJiaGou as the research object,It based on field surveys and data collection,proved up the reserves and distribution of the slag source,the historic activity and main characteristics of debris flow,the motion characteristics of debris flow are analysised and the characteristic parameters are calculated.Two main starting ways of slag debris flow are obtained through the laboratory simulation test,and the mechanical processes of the two kinds of starting methods are analyzed.At the same time,from the factors of particle size distribution,initial water content and source accumulation mode,three other variables are controlled,and three factors are studied for debris flow.The influence of starting mechanism is studied,and the correlation function between the variables and the critical water quantity of debris flow is explored by regression equation.According to the dynamic characteristic parameters and the test results,the prevention and control model of the slag-type debris flow in XuJiaGou were put forward.The main research work and achievements of this article are as follows:(1)Through field investigation,the Watersheds Area of slag type debris flow in XuJiaGou is 12.415 km2,the length of main ditch is 6.89km,average vertical ratio drop of main groove 212.6,the Slag Source is 76.04×104m3and which is 40%of total sources,the average annual precipitation is 900mm,the maximum annual rainfall is1113.7mm.(2)Through field investigation of the topography,source condition and water condition of debris flow,Combined with the history of debris flow,the formation mechanism of XuJiaGou is"erode-slide-block-break-form debris flow-scour-block-tailings dam break-form twice debris flow"and the major developmental characteristics of XuJiaGou is heavy rainfall,abundant source of resources,multiple blocking points,huge threat,etc.(3)Based on the formation mechanism and development characteristics of the Xujiagou slag debris flow,Analysis and calculate bulk density of debris flow is1.80t/m~3.The representative section II-II'velocity is 2.97 m/s,The peak flow rate of debris flow is 327.89 m~3/s,the overall impact force of the debris flow is 36.23KN,and other dynamic characteristic parameters.(4)from three factors which affect the particle gradation,initial moisture content and the source accumulation mode of the debris flow starting by the indoor simulation test,the control of the other variables is the same,the study concludes that The more fine particles content,the less critical water flow starting,the Non-uniform coefficient Cu the larger,the harder it is to start the debris flow;Initial Moisture Content(P)to 3%~13%,the higher the initial water content,the higher the critical water value of the debris flow starting,the larger the starting material source;Initial water cut rate(P)to16%~19%,the higher the initial water content,the smaller the critical water value,the larger the starting material source;Initial moisture Content When(P)is 15%,debris flow is difficult to start at a relatively small flow rate,and the critical initial moisture content that is most detrimental to the start of debris flows is 15%;Critical starting water of rectangular section>Critical starting water of trapezoidal cross section>Critical starting water of triangle section,Starting source ratio of rectangular section>The starting source ratio of the trapezoid section>The starting source ratio of the triangle section.According to the influence of the three factors on the starting mechanism of the debris flow,the correlation function of the critical water quantity of the variable and the debris flow is investigated by the regression equation,and preliminary study on the starting mechanism of slag debris flow.(5)According to the research of the mechanism of slag type debris flow starting test phenomenon and as a result,summarizes the slag type debris flow starting two main ways:"erode-slide-block-break"type and the start type of bottom tearing scouring groove-bed,and analysis the simplified process of the two starting ways and mechanical changes.(6)According to the development characteristics and kinetic parameters of the slag-type debris flow in XuJiaGou,combined with the existing engineering,This article proposed the control mode of"geotechnical engineering,biological engineering and monitoring early warning"and the prevention and control countermeasure of"ditch cleaning,put the slope,unilateral protective dyke,block dam"...