Numerical Simulation Study On Debris Flow Characteristics And Movement Process Of Guanmen Gully In Fengxian County

The closure ditch is located in pingkan town,fengxian county,baoji city,shaanxi province.It is located at the southern foot of qinling mountains.The mountain is high and deep,the terrain is steep,and there are lead and zinc mineral resources underground.However,since the mining of lead and zinc mine in the gully,a large amount of slag was dumped irnto the gully,and the debris flow occurred again in July 2013.Due to the large amount of waste material,the debris flow has the characteristics of mine debris flow,which washed away the houses and industrial sites in the gully,seriously threatening the life and property safety of residents in the gully.This paper studies the debris flow in guomen gully,fengxian county,and studies the basic characteristics and movement process of the debris flow,hoping to provide scientific basis for the prediction,early warning and disaster reduction of mine debris flow.Based on the comprehensive analysis of geological environment conditions and rainfall characteristics in mengmengou basin,it is concluded that the debris flow in mengmengou basin is medium-frequency,sparse,rainstorm and gully debris flow.Based on the relationship between the main factors affecting the formation of debris flow and the formation,development and movement of debris flow,the mechanism of debris flow formation is analyzed.In the mature and old age,hydraulic erosion is the main and gravity erosion is the auxiliary.The method of qualitative analysis and quantitative evaluation is adopted to evaluate the susceptibility of debris flow.Based on the characteristics of landslide engineering geology analysis,based on PFC-2 d simulation software,built close gully particle flow model,carried on the thorough research of debris flow movement process,think of closed gully movement process can be divided into two stages:the first stage for bus shaped stage,the second phase to discharge sediment phase;Based on the numerical simulation results,the disaster consequences of debris flow are analyzed.The maximum distance of debris flow and deposition is 780.34m,and the thickness of debris flow and deposition is 11.99m at the mouth of the ditch.The debris flow and deposition are as far as the other side of yinmu si river,flooding the mouth adit,which poses a great threat to the life and property of the residents in the mouth.The average velocity of each monitoring point is 4.39m/s,which is close to the flow velocity parameter(4.54m/s)obtained by theoretical calculation.Relevant research methods and results of this paper can provide necessary reference for the basic characteristics,formation mechanism and dynamics analysis of similar debris flows.