Influence Of Rainfall Infiltration On Slope Stability In Gully Of Bainaimiao Coal Mine Engineering

The slope of artificial soil covering engineering is not covered by vegetation,and the slope is steep.Once runoff is formed,it is bound to cause soil erosion and even the overall destruction.It is an important approach to understand the influence of soil erosion on slope stability to study the formation reason of slope gully and the characteristics of rainfall infiltration in open pit coal mine engineering.This paper systematically analyses and summarizes the formation reasons and classification of gullies.The gully formation of artificial engineering slope in open-pit mine is produced under the comprehensive action of various factors,the main factors include stratum structure,side slope surface property,soil rebound deformation.According to the development stage of gully,gully of slope engineering in Bainaimiao Coal Mine can be divided into four types:gully,rill,gully and gully.According to the continuity of gully,slope gully can be divided into two types: discontinuous gully and continuous gully.According to the cross-sectional morphology,it can be divided into U type and V type gully type.According to the scale of gullies,gullies are divided into large gullies and small gullies.According to the field investigation,it is determined that the typical slope gully of Bainaimiao Coal Mine is a small continuous V-shaped gully.Taking the slope of artificial restoration project in Bainaimiao Open-pit Coal Mine in Inner Mongolia as the research object,the law of gully rainfall infiltration and the influence of gully infiltration on slope stability were analyzed by using finite element analysis software ABAQUS.The seepage law of slope in the process of rainfall was analyzed by numerical simulation,and the influence of different size and form of gully rainfall infiltration on slope seepage was compared.The stability of different slopes after rainfall was analyzed by strength reduction method.Comparison and analysis the different condition of gully slope rainfall infiltration,gully permeability on the influence law of slope rainfall infiltration and slope stability,the results show that:(1)the larger intensity of rainfall will be formed in the surface layer of slope soil outside local high water-cut zone,and gradually to the inside slope soil permeability,moisture content and saturation changes gradually;(2)The existence of gullies will increase the pore water pressure and saturation of soil surface,especially gullies.Under the same rainfall condition,gully infiltration will make the water level inside the soil higher,reduce the stability of the slope,and cause greater security hidden danger to the structure.(3)The existence of gullies will reduce the safety of the slope.Under the same rainfall condition,different gullies have different effects on the infiltration and stability of the slope.Under the effect of gully rainfall infiltration,the wider the gully width is,the deeper the gully depth is,and the deeper the infiltration range is,the higher the water content in the slope is and the faster the growth rate is,the lower the slope safety is.Excessive gully will change the plastic development law of slope and form the phenomenon of soil flow at the gully at the slope foot.This study provides a scientific basis for the control effect of gully erosion and the treatment of gully slope,and provides a reference for the establishment of landslide warning mechanism of gully slope in Bainaimiao Coal Mine.