元宝山露天煤矿3~#排土场工程地质条件与稳定性分析预测

Engineering Geological Condition and Stability Analytical Prediction of No.3 Waste Dump in Yuanbaoshan Surface Coalmine

在分析矿区地形地貌、地层岩性、水文地质条件和影响排土场稳定因素的基础上,结合区内2#排场的监测资料,采用FLAC3D模拟软件和刚体极限平衡法中的毕肖普条分法,对排土场边坡变形、破坏的主要影响因素进行了分析,揭示了其滑坡机理;对3#排土场的稳定性做出预测,认为排土场边坡变形破坏模式是上部排弃物沿圆弧滑面剪切滑移与下部沿粉土、粉质粘土平面滑移的圆弧—平面组合滑移形式;基底土层的内摩擦角对排土场允许排高较为敏感,是决定允许排高的内在因素,基底粉质粘土的极限承载力是决定排土场允许排高的外在因素;基底土体极限承载力所决定的排土场的允许排高为90.60～91.60m。提出了填沟压脚、降低第一排台阶高度和基底排水等措施来满足排土场边坡稳定的要求。

Based on mine area topography,landform,strata,lithology,hydrogeological condition and factors impact waste dump stability,combined with No.2 waste dump monitoring data,using FLAC3D simulation software and Bishop slice method in rigid body limit equilibrium method carried out analyses for waste dump slope deformation,main failure impacting factors and unveiled landslide mechanism.The prediction of No.3 waste dump stability has inferred that the slope failure is arc-planar integrated mode of shear gliding of upper part waste along circular arc and lower part along silt,silty clay planar gliding.Internal friction angle of basement soil is relatively sensitive to dumping height allowance,thus the intrinsic factor to determine the allowance;while ultimate bearing capacity of basement silty clay the external factor that determined dump height allowance is 90.60~91.60m.Measures of backfilling presser foot,lowering down the first dumping bench height and basement drainage to ensure waste dump slope stability have been put forward.