软岩露天煤矿边坡稳定性分析及形态优化研究

Research on Slope Stability and Morphology Optimization of Soft Rock Open-pit Coal Mine

针对露天煤矿软岩边坡强度较差,遇水结构易崩解、泥化、强度急剧下降导致露天矿在开采过程边坡稳定性难以控制的问题。研究了复杂地质条件下露天煤矿的边坡稳定性,通过分析边坡工程地质情况和地层赋存特点,提出了以各个弱层为滑移面自上而下的边坡形态逐水平优化方法,将此方法应用于白音华一号露天煤矿首采区东帮,分别对2个方案进行稳定性分析,通过对比优化确定的边坡到界形态。研究结果表明:白音华一号露天煤矿东帮容易发生顺层滑坡,采用沿底板留设宽平盘逐水平优化的方法,边坡局部沿2^(#)煤底板留设平均为85 m的宽平盘,其余各平盘宽度为35 m,将东帮终了边坡进行局部加陡,最终边坡角从11°~16°,3-1^(#)煤底板以上边坡整体及局部稳定性系数分别为1.163和1.16。方案2比方案1多剥离10612.3万m^(3),多采煤2913.9万t,方案2剥采比为1.6 m^(3)/t。

In view of the poor strength of soft rock slope in open-pit coal mine,the water structure is easy to collapse,argillization,and the strength decreases sharply,which makes the slope stability of open-pit mine difficult to control during mining.The slope stability of open-pit coal mine under complex geological conditions is studied.By analyzing the engineering geological conditions of the slope and the occurrence characteristics of the strata,a horizontal optimization method for the slope morphology from top to bottom with each weak layer as the sliding surface is proposed.This method is applied to the east side of the first mining area of Baiyinhua No.1 open-pit coal mine,and the stability of the two schemes is analyzed respectively.The boundary morphology of the slope is determined by comparison and optimization.The research results show that the east slope of Baiyinhua No.1 open-pit coal mine is prone to bedding landslide.By using the method of horizontal optimization with a wide flat plate left along the floor,the local slope is left with a wide flat plate with an average of 85 m along the No.2 coal floor,and the width of each flat plate is 35 m.The end slope of the east slope is locally steepened,and the final slope angle is from 11°to 16°.The overall and local stability coefficients of the slope above the No.3-1 coal floor are 1.163 and 1.16,respectively.Scheme two stripping 106.123 million m^(3)more than scheme one,mining 29.139 million tons more,scheme two stripping ratio 1.6 m^(3)/t.