极近距煤层(群)间夹矸层处理与利用

Treatment and utilization of dirt band between contiguous coal seams

以官地矿28416工作面为背景,通过理论分析、数值模拟及现场实测对极近距煤层(群)间夹矸层的处理与利用进行研究。结果表明:1)错层位工作面可高效率利用巷道进尺探测泥岩厚度,不论能否合采都不会造成巷道浪费;2)错层位工作面穿层为夹矸层和顶煤创造临空自由面,提高了冒放性,适当降低支撑力可加快夹矸破断;3)错层位布置巷道充分利用泥岩夹层天然地质条件维护巷道,泥岩夹层控制了错层位巷道顶底板围岩塑性区扩张,提高了围岩完整性和稳定性;4)错层位布置降低了28416工作面采空区边缘下方接续面进风巷围岩应力,避免了支承压力影响,且减小了接续面进风巷围岩塑性破坏范围,提供了较完整围岩环境,有助于隔绝顶部采空区;5)错层位巷道支护效果良好,节省支护费用近50万元,回采率得到大幅提升,增加效益1.38亿元。

Taking 28416 working face in Guandi coal mine as the engineering background, theoretical analysis, numerical modeling and field measurement were conducted to study the treatment and utilization of dirt band between contiguous coal seams. Conclusions are as follows： 1） The split-level working face leads to an efficient use of roadway during driving to explore the thickness of the dirt band. The roadway will not be wasted regardless of that the coal seams are proper to be mined or not. 2） The cross measure panel creates free face for dirt band rock bed and top coal which increases caving ability, and appropriately decreasing supporting force is beneficial for breaking the rock bed. 3） The split-level working face makes full use of natural condition of the mudstone bed to maintain the roadway. The mudstone interbed constrains the plastic zone expansion of the roof and floor of the split-level roadway and strengthens the stability and integrity of surrounding rock mass. 4） The split-level working face arrangement reduces surrounding rock stress of the continuous airway under the edge of the gob area of the 28416 working face, avoids the influence of the abutment pressure, and reduces the plastic damage scope of the surrounding rock mass of intake airflow roadway of the successive panel, providing more complete surrounding rock environment to help to isolate the gob. 5） Support for split-level working face of the roadway is satisfactory, saving 0.5 million RMB, increasing recovery ratio significantly and obtaining 138 million RMB as benefit.