基于端帮开采的边坡稳定性及巷道布置形式优化研究

Study on slope stability and roadway layout optimization based on end-slope mining

为高效、安全回采露天矿开采后端帮大量压煤,查明端帮开采下群巷效应所引起的边坡变形和应力重新分布特征,保证边坡稳定安全;以某露天矿为工程背景,通过分析端帮开采煤柱应力分布特征来确定合理的端帮开采煤柱设计参数;采用Midas GTS NX有限元数值模拟来研究端帮采煤所引起边坡的受力和变形特征及验证边坡稳定性;进一步通过优化采巷布置形式来提高回采率。研究结果表明:对于端帮厚煤层开采而言,煤柱强度、尺寸及采巷布置形式是影响边坡稳定性的主控因素;单、双排采巷布置下整体边坡安全系数分别为1.21、1.14,边坡安全性降低,但仍能够满足安全系数要求;端帮压煤回采率将提高5%,能够有效回收端帮压覆资源量。

In order to efficiently and safely mine the end-slope pressure coal left after the open-pit mining, find out the slope deformation and stress redistribution characteristics caused by the group roadway effect under the end-slope mining, and ensure the slope stability and safety, taking an open-pit mine as an engineering background, through analyzing the stress distribution characteristics of the end-slope mining pillar, the reasonable design parameters of the coal pillar for end slope mining are determined. The Midas GTS NX finite element numerical simulation is used to study the stress and deformation characteristics of the slope caused by end-slope mining and verify the slope stability. Furthermore, through the optimization of roadway layout to improve the recovery rate. The results show that: for the mining of thick coal seam with end-slope, the strength, size of coal pillar and the layout of mining roadway are the main control factors affecting the slope stability. The overall slope safety factors of single row and double row roadway layout are 1.21 and 1.14 respectively, and the slope safety is reduced. However, the overall slope can still meet the requirements of safety factor, and the recovery rate of end-slope coal will be increased by 5%, which can effectively recover the amount of end-slope overburden resources.