极近距离薄煤层群联合开采常规错距理论 与物理模拟

 伴随着中、厚煤层资源的枯竭，潞安集团下属十几个矿井都将进入下组煤开采。下组煤15–1#和15–3#煤层是以薄煤层群赋存在一起，平均间距为4.4 m，因此提出极近距离薄煤层群联合开采常规错距开采模型，并进行理论和物理模拟试验研究。从理论上给出近距离薄煤层群联合开采下的工作面常规错距计算公式，并进行理论求解。为避免15–1#煤层顶板的周期垮落与15–3#煤层工作面回采时的超前效应相互影响，从安全角度考虑，将错距定为1.3～1.5倍的周期垮落步距，结合试验结果将常规错距定为17.5 m。物理模拟试验结果表明，常规错距下联合开采技术上是可行的。另外分析了工作面上方附近几个测点总是被抬高的原因，并总结了在工作面推进过程中，顶板下沉主要经过两次大的变化，即上、下两煤层工作面回采过程中发生垮落时，尤其是下层煤顶板垮落造成影响较大。

THEORY AND PHYSICAL SIMULATION OF CONVENTIONAL STAGGERED DISTANCE DURING COMBINED MINING OF ULTRA-CLOSE THIN COAL SEAM GROUP

With the resources exhaustion of medium-sized thickness and thick coal seam，more than 10 mines will be transferred to the lower coal group in Lu¢an Group. The occurrence mode of coal seams #15–1 and #15–3 in the lower coal group is thin coal seam group with average distance 4.4 m. Therefore，the conventional staggered distance model of ultra-close thin coal seam group during combined mining is put forward；and the theoretical research and physical simulation are carried out. The conventional staggered distance formula is proposed. To avoid interaction between the roof periodic caving of coal seam #15–1 and the leading effect of coal seam #15–3 in mining，from the point of safety，the conventional staggered distance is confirmed as 1.3–1.5 times of the roof periodic caving span of coal seam #15–1. Combined with the experimental results，the conventional staggered distance is determined as 17.5 m. Physical simulation test results show the feasibility of the conventional staggered distance in combined mining. In addition，the elevation reason of several measuring points on the top of the working face near coal seam #15–1 is analyzed；and the roof subsidence phenomenon，which has mainly two major changes during the course of working face advance，namely，the roof caving in the stoping course of upper and lower working faces，is summarized，especially the roof caving of lower coal seam which will have larger influence.