Research On Soil Erosion Process Of Different Soil And Water Conservation Engineering Measures On Dump Slopes

Soil drainage field is the most serious area of water and soil erosion in open-pit coal mines.Most studies on soil drainage field focus on soil water holding and storage capacity,analysis and estimation of ecological and environmental benefits,and the role and extent of soil fertility restoration,etc.There are relatively few studies on the hydrodynamic parameters and benefits of flow and sand reduction of soil and water conservation engineering measures in the prevention and control of slope surface of soil drainage field.This paper takes the slope of the open pit coal mine drainage field as the research object,adopts the indoor artificial simulation rainfall experiment method,analyzes the changes of hydrodynamic parameters,runoff rate,sand content and erosion rate with time under the non-engineering measures(narrow ridge horizontal ditch,wide ridge horizontal ditch,geotextile bag 30% and geotextile bag 50%)and rainfall intensity(60,90,120 mm/h),and researches the change law between soil erosion rate and hydrodynamic The quantitative relationship between soil erosion rate and hydrodynamic parameters was investigated to reveal the flow and sand reduction benefits of engineering measures,with a view to providing a scientific basis for the erosion control of open pit coal mine drainage sites.The results show that the average flow velocity,Reynolds number,Froude number and runoff power of slope surface with different rainfall intensity under different engineering measures are as follows: narrow ridge horizontal ditch > wide ridge horizontal ditch > no measure > geotextile bag 30% > geotextile bag 50%,and the resistance coefficient and runoff shear force are as follows: geotextile bag > no measure > horizontal ditch.Geotextile bag measures have obvious effects in reducing runoff velocity,erosion volume,erosion rate,runoff ditch depth and ditch width,and have good regulation effect on slope surface flow reduction and sand reduction,of which the best effect is achieved when geotextile bag 50% cover.Different rainfall intensity can affect hydrodynamic parameters,runoff rate,sand content and erosion rate.Soil erosion rate is highly significantly and positively correlated with flow velocity,Reynolds number,Froude number,runoff shear and runoff power,and highly significantly and negatively correlated with resistance coefficient.In summary,the deployment of engineering measures can increase the seepage storage capacity of the slope of the drainage field,regulate the surface runoff and reduce the flow rate of the slope to achieve the effect of flow reduction.Comparing different engineering measures,it can be seen that the slope surface flow reduction and sand reduction effect is the best when the geotextile bag is 50% covered.According to the equations of(CNt/CN)and(Pr/S)logarithmic functions constructed by SCS-CN model,the slope surface runoff under different engineering measures of the drainage field can be simulated better.The thesis has 27 pictures,6 tables and 109 references.