Research On The Development Characteristic And Contorl Engineering Of Houshan Gully In Yaoshan Town,Qiaojia County,Yunnan

As a common geological disaster,debris flow often has a huge impact on the production and life of the occurrence area.Direct or indirect casualties and economic losses are even more incalculable.It mainly occurs in the high and precipitou mountainous areas.Rainfall is one of the inducing factors that cause it to occur.The lack of early exploration often makes the occurrence of debris flow unpredictable.The sediment mixture and the huge gap of the mountain often make it At higher speeds,the main substances such as silt stones carried are causing great damage to the downstream.At the beginning of the study of debris flow,it was mainly accomplished by statistical empirical formulas and mathematical models.With the development of computer technology in recent years,scholars at home and abroad have used numerical simulations that combine the model equations of debris flow force.The formation,development and flow accumulation of debris flow are simulated and analyzed,and the debris flow disasters are predicted and forecasted to provide reference for the design of debris flow disaster prevention and mitigation.The research object of this paper is the large-scale debris flow in Yaoshan Town,Qiaojia County,Yunnan Province,which occurred in 1989,2012 and 2014.In particular,a large amount of solid materials rushed out in 2014,and caused a short period of blockage of the drainage channel in deposition zone,which was insufficient for its narrow and gentle,the sediments buried the campus could reach to 3.5×104 m2.Based on the actual data of the Houshan guly exploration record,this thesis summarizes the geological environment in the formation area and the development characteristics of the weak structural surface,and calculates the dynamic parameters of the debris flow.The three-dimensional fluid domain model of the Houshan guly accumulation area was established by Sufer software.The threedimensional numerical modeling of the Houshan guly was carried out in combination with the fluid dynamics software CFX,so that the three-dimensional flow field in the Housan guly area can be visually displayed.Based on the historical data related to the Housan guly,the three-dimensional flow field model that best matches the actual geological conditions of the Housan guly is found,and the area where the debris flow geological disaster is easy to be demarcated is delineated.The debris flow control engineering measures are proposed through the obtained danger zone range,and the established model is used to pre-simulate the slippery area delineated by the experiment,and the proposed control measures are judged according to the simulation results.conclusion as below:(1)According to the detailed study of the regional geological environment and the basic characteristics of the Houshan guly debris flow.It is concluded that the debris flow is a turbulent guly debris flow with medium frequency and medium-sized mainly triggered by rainfall.(2)Through the quantitative analysis and calculation of the characteristic parameters of Houshan guly debris flow by "morphpmetric investigation" and "rain-flood method".It is concluded that the debris flow in 2014 is close to the once in 30 years,and the debris flow in Houshangou is blocked by using flow discrimination method.the 30-year frequency debris flow and 50-year frequency debris flow are not possible to block the river.(3)According to use CFX software to simulate the 30-year and 50-year debris flow in Houshan guly,and the whole process of debris flow and accumulation in Houshan guly was analyzed.By comparing with the dangerous area of debris flow in 2014,the simulated oncein-30-year debris flow is basically consistent with the actual area of debris flow in 2014,which proves that the numerical simulation of debris flow using CFX software is reliable.(4)Based on the control objectives and prevention principles of Houshan guly,this thesis proposed control facilities such as blocking facilities,drainage dikes,drainage channels,and numerical simulations were carried out to add the treatment facilities.The results show that the scope of debris flow dangerous area is obviously reduced after the treatment project is set up,which will not pose a threat to the residents and schools in the accumulation area.This verifies that the proposed control measures have a good control effect on the debris flow in Houshan guly.