Research On Characteristics And Treatment Of Qifenshui Village Debris Flow In Guilin

Quanzhou county in northern guangxi is a region with frequent geological disasters,especially debris flow.This paper collects,investigates and statistically analyzes a large amount of indoor and outdoor data on the debris flow in guilin.From the perspective of engineering geology,taking the geological environment background of debris flow area as the entry point and combining with the experiment of geotechnical characteristics,the influencing conditions and development characteristics of the formation of seven-component water debris flow are analyzed.The dynamic parameters of the debris flow are calculated.The risk of debris flow is evaluated by fuzzy comprehensive evaluation method and traditional debris flow evaluation method.Finally,the control measures for the debris flow are put forward.The main research work and results of this paper are as follows:1.On the basis of collecting and analyzing the existing geological data of debris flow,a detailed field survey of debris flow area is made.The geological environment background,forming conditions and influencing factors of debris flow are analyzed.2.The experimental study on the rock and soil characteristics of the soil mass in the debris flow source area shows that:the soil mass in the debris flow source area has large grain size,sharp grain Angle,basically no roundness and good permeability.The cohesive force and internal friction Angle of soil decreased with the increase of water content.The whole rock analysis of the source soil shows that the highest content of quartz is 56%,the content of clay is 15%,the content of microcline is 13%,the content of plagioclase is 10.5%,and the content of bauxite is 5.5%.The clay analysis of the source soil showed that the highest content of kaolinite was 58.5%,the rest were illite and vermiculite mixed layer 16.5%,illite and 14.5%,and vermiculite 10%.3.The topography,physiognomy,water source and vegetation conditions affecting debris flow outbreak were studied and their relationships were analyzed.4.The characteristics of clear water area,forming area,circulation area and accumulation area of debris flow are analyzed.To calculate the debris flow characteristic parameters,including:severe 1.738 t/m~3,velocity of 8.56 m/s,the rock movement speed 3.5 m/s,flow of297.21 m~3/s,a total flow of 108066.18 m~3,the quantity of solid material out of 50159.02 m~3,the overall impact pressure Pa,stone impact 525.00 KPa,climb 3.7,use a height of 5.8 m,debris flow ditch into the estuary section carrying capacity is 2366 m~3/h.The classification of debris flow was determined by comprehensive analysis method.5.Debris flow risk assessment USES two evaluation models,and the evaluation results show that the risk level of seven-component water debris flow is moderate risk.6.The measures to prevent and control debris flow are determined as follows:the combination of flexible bar grid,pile group,comb dam,gabion dam,anti-erosion diversion dike and drainage channel.Checking the storage capacity and stability of the designed control measures,the results show that the designed control measures meet the requirements.