Analysis on effect of different discarded materials on slope stability at the bottom of open-pit coal mine dump

LYU Guilong

doi:10.13235/j.cnki.ltcm.20240168

Abstract：To analysis on effect of differemt discarded materials on slope stability at the bottom of open-pit coal mine.This article focuses on the stability problem of the dump slope in open-pit coal mines,taking Hequ Open-pit Mine as an engineering example,and systematically studies the mechanical behavior and stability characteristics of the slope under different bottom material conditions.The article uses automatic triaxial compression test to obtain the shear strength parameters of loess,fine sandstone,coarse sandstone and mudstone under different confining pressures,and constructs a dump slope model to analyze the stress-strain distribution and the location of potential sliding surfaces under different bottom material layer strengths and thicknesses.At the same time,we use multiple limit equilibrium methods to calculate the stability coefficients under various working conditions.The results show that regardless of whether fine sandstone,mudstone or coarse sandstone is used as the bottom discard layer,the slope presents a typical overall bottom-cutting circular arc sliding failure mode.However,the mechanical properties and thickness changes of the bottom material have significant differences in their influence on the stability coefficient.As the thickness of the bottom fine sandstone layer increases,the safety factor increases from 1.268 to above 1.324,showing a significant gain effect;while the safety factors of the bottom mudstone and coarse sandstone layers decrease slightly to significantly with the increase in thickness,and the coarse sandstone layer even drops below the safety threshold of 1.2 when the thickness reaches 72 m.