Study on Fixed Boundary of Steep End-slope Mining Based on Stability Analysis

Based on the theory and practice of steep end-slope mining,when dangerous sliding surface only exists in the local area of slope,in light of the distribution situation of sliding surface,the paper puts forward a method to redetermine fixed boundary for steep end-slope mining.By GEO-studio software,the stability analysis of slope with different boundary height and different slope angle was made for steep end-slope mining,and the positive effect of inner-dumping with burying slope was proved.It was concluded that the fixed boundary of steep end-slope mining was 50 m in height from the bottom of slope,the slope angle of underpants could increase to 46° in Sandaoling surface coal mine.The results of study showed that when the fixed boundary is redetermined based on slope stability analysis,steep end-slope mining can be implemented effectively,so the stripping ratio can be reduced to 1.84 m3/t,and the recovery amount of coal in length of a metre along the strike can be increased by 273.376 t.