近距离煤层采空区下工作面矿压规律研究

发布时间：2018-06-22 09:07

  本文选题：近距离煤层 + 侧向应力　； 参考：《安徽理工大学》2015年硕士论文

【摘要】：本文结合朔州山阴县南阳坡煤矿工程地质条件,针对近距离煤层开采过程中采空区下综放工作面出现的巷道围岩变形严重的问题,运用理论分析、数值模拟、现场工程实践相结合的综合研究方法,对回采工作面巷道两帮侧向压力分布及下煤层巷道支护设计进行了研究。 利用岩层质量指数法,对顶板岩层每一层进行岩层完整性和坚硬程度评价,得出下层煤综放面上覆直接顶最终垮落并填满采空区；基于传统矿压理论,计算得出直接顶的垮落高度为23.7m,老顶来压当量为893kPa,根据老顶分级指标,确定老顶等级为Ⅰ级,老顶来压显现不明显；基于结构稳定性指数,对巷道围岩进行分类,由于4105运输顺槽受构造及上煤层开采影响,巷道属于中等稳定。 根据FLAC3D数值模拟结果,得出4105运输顺槽变形受3-2煤开采支承高压力、区段煤柱尺寸不合理造成的侧向压力影响,将4107回风顺槽的区段煤柱从46m改为38m,能够有效降低3-2煤开采支承高压力影响,3-2煤开采后,滞后60m左右覆岩停止运动,故下层煤可滞后3-2煤工作面60m开始割煤。如果考虑构造影响(根据现场应力及表面位移观测),在合理的近距离采场布局情况下,应滞后120m开采4-1煤。 根据覆岩运动规律,建立了“顶煤+直接顶岩层+垮落带岩层”结构模型,通过理论计算,得出下层煤综放支架合理工作阻力应不小于9690KN,所选液压支架额定工作阻力为10000KN,因此,正常来压时,依靠支架可以保证工作面的支护安全。为了改善巷道变形严重的问题,对巷道支护设计进行了优化,分别对稳定性围岩及非稳定性围岩两种情况下的支护进行了设计；现场观测表明,对巷道支护进行优化设计后,巷道围岩变形量变小,锚杆、锚索工作载荷均能达到合理值,能够保证回采巷道的稳定性,说明经过优化设计的巷道支护方案可以满足现场要求。
[Abstract]:Combined with the engineering geological conditions of Nanyang slope coal mine in Shanyin County of Shuozhou, aiming at the serious deformation of surrounding rock of roadway under fully mechanized caving face under goaf in close distance coal seam mining process, this paper applies theoretical analysis and numerical simulation. Based on the comprehensive research method of field engineering practice, the lateral pressure distribution of two sides of roadway and the support design of roadway in lower coal seam are studied. By using the method of strata quality index, this paper evaluates the integrity and hardness of each layer of roof rock, and concludes that the top directly overlying top of fully mechanized caving face of the lower coal will eventually collapse and fill up the goaf, which is based on the traditional theory of rock pressure. The calculation shows that the collapse height of the direct roof is 23.7m, the equivalent of the main roof pressure is 893kPa.According to the index of the classification of the main roof, it is determined that the grade of the main roof is grade 鈪，

本文编号：2052331