Study On Deformation Law Of South Slope Of High And Steep Weak Strata In West Open-pit Mine Of Fushun

After 100 years of mining,the West open-pit Mine in Fushun has formed a very large deep open-pit mine.With the increase of its depth,the stability of the high and steep slope in the open-pit mining area becomes more and more obvious.In order to study the deformation law of high and steep bedding slope in West Fushun Open pit mine,field investigation,theoretical analysis,field monitoring data analysis and numerical simulation are used in this paper,according to the characteristics of the high-steep bedding slope in the South Slope of West Fushun open-pit Mine,two control measures of backfilling foot and groundwater are put forward.The main results are as follows:(1)The Geological Survey and literature collection of the South Slope of the West open-pit Mine in Fushun showed that the south slope of the West open-pit Mine in Fushun is a high and steep slope with many weak interlayers,the dip angle of weak interlayer and its physical and mechanical properties are the internal causes of slope instability.The excavation and rainfall-groundwater activities are the direct causes of slope sliding and large deformation.(2)The results show that the failure mode of the South Slope in West Fushun Open pit mine is a slip-bend-shear type,which is combined with the deformation and failure characteristics and deformation rate of the slope,the whole process of slope deformation is divided into three stages: the initial sliding stage,the accelerated sliding stage and the disaster shearing stage.(3)The numerical simulation of high and steep bedding slope in West Fushun Open pit mine shows that the slope is unstable under the action of the third stage excavation and rainfall-groundwater,and the sliding range is larger under the action of rainfall-groundwater.The failure process of the slope is as follows: The back edge of the slope is damaged by tension,and the depth of deformation is the largest when the third stage is excavated;the middle and upper parts of the slope are deformed by sliding,sliding along the direction of the weak layer of the slope;the middle and lower parts of the slope are deformed by bending when being squeezed,the shear failure occurred at the foot of the slope,which was most obvious under the action of the third stage excavation and rainfall-groundwater.(4)In order to clarify the characteristics of the boundary of the landslide,the In SAR interferometric radar technique,the SSR slope stability radar technique and the Mai remote sensing monitoring technique were used to analyze the boundary of the south slope,finally,the South Slope is defined as: The main fracture in W500 ? W800 lateral line on the western boundary;F5 fault on the eastern boundary;two ground fissures at the top of the South Slope on the southern boundary;and the bottom drum at the bottom of the slope on the northern boundary.(5)Aiming at the high and steep slope of the South Slope of the West Fushun Open pit mine,this paper puts forward the prevention and control measures of the combination of the backfilling foot and the prevention and control of underground water,and carries out the numerical simulation calculation of the backfilling 50 m and 100 m respectively,the displacement of the slope can be effectively reduced by backfilling the toe,the Factor of safety of the slope is1.04 when the backfilling is 50 m,the Factor of safety is 1.12 when the backfilling is 100 m,the factor of safety of the slope is increased,and the slope is basically stable when the backfilling is100 m.It is found that the slope stability is accelerated and the slope deformation is alleviated effectively when the closed pit slope is filled with water.There are 53 figures,8 tables and 73 references in this paper.