Study On Water Retention And Erosion Characteristics Of Slope Modified In Dump

Rainfall is one of the important factors causing soil erosion and stability reduction of open-pit dump slope.In Eastern grassland area of China,water resources are relatively scarce and soil erosion is relatively serious.It is of great significance to enhance the water retention and erosion resistance of dump slope to realize effective reclamation and ecological restoration of mining area.Therefore,this paper analyzes the erosion characteristics and stability changes of 4 types of slopes under the influence of different rainfall,angles and heights,and reveals the positive role of Anti-S-Type slope in reducing soil erosion and enhancing the water holding capacity of slopes.Based on the theoretical analysis,this paper compares the distribution characteristics of raindrop splash erosion,rill erosion and seepage erosion slope on different types of slope.It shows the influence of angle change on rainfall erosion process,and reveals the migration law of bed load and suspended load particles in slope runoff.According to the distribution of effective rainfall intensity,the influence of slope angle on the distribution of soil water resistance characteristics is further explained.In this paper,the evaporation,soil moisture,runoff and sediment characteristics and soil erosion of four types of slopes under different rainfall conditions were measured by rainfall simulation experiment in laboratory.The results show that: under the effect of a single heavy rainfall,the cumulative evaporation of different types of slopes increases nonlinearly with time,and the overall relationship meets the requirements of Anti-S-Type slope<Uniform slope<S-Type slope<Concave slope.With the increase of slope angle,the degree of soil moisture decrease gradually,the sediment yield decreases in a fluctuating manner,the initial runoff time decreases,and the relationship of runoff meets the requirements of Anti-S-Type slope<Uniform slope<Concave slope<S-Type slope.When the slope angle is low,it is conducive to rainwater infiltration,and the proportion of runoff in soil and water loss is relatively small.Under intermittent rainfall,due to the high surface soil moisture content,the decreasing trend of soil moisture is relatively close.With the increase of rainfall frequency,the initial runoff time decreases significantly,the time required to reach stable runoff decreases,the stable runoff increases,and the sediment yield decreases.The overall soil erosion and soil erosion characteristics of the 4 types of slopes are similar to those of the single heavy rainfall experiment The results show that the Anti-S-Type slope has less erosion,less soil and water loss,and stronger water conservation and erosion resistance.Based on the actual layout of the dump in the eastern grassland mining area,the corresponding numerical simulation model is established,and the redistribution of pore water pressure and the stability of the slope are analyzed with or without rainfall.The results show that: with the increase of slope angle and height,the stability of concave slope and S-shaped slope shows a greater weakening trend,and there are different degrees of water outflow at different heights of slope surface,the overall decline of safety factor is larger,while the overall weakening degree of anti-s-shaped slope is lower,which has good rationality and feasibility in practical application.There are 46 figures,11 tables,100 references in this thesis.