针对近距离煤层开采时,上层煤开采会对下层煤产生采动影响,导致下层煤邻近回采巷道围岩变形等问题,提出了近距离煤层错层位切顶卸压护巷技术。分析了错层位切顶卸压护巷技术原理,推导出近距离煤层错层位切顶高度的计算公式,给出错层位切顶的关键参数,研究了错层位切顶卸压护巷效果。结果表明:通过错层位切顶主动调控顶板断裂位置可缩短悬臂梁长度,同时切落后的岩石因受到采空区与夹层的缓冲作用减少能量向下传递,有效保护了下层巷道的围岩稳定;错层位切顶高度的确定需考虑顶板垮落的矸石对本层位空区与下分层空区的充填效果,以及层间岩石的垮落影响。现场工业性试验发现,错层位切顶后,动压巷道底鼓量由3.0m降至0.5m左右,降幅为83%。

Upper coal mining will have mining influence on lower coal when mining in contiguous seams, resulting in the deformation of the surrounding rock of the mining roadway near the lower layer coal. The technology of split-layer roof cutting and pressure relief for roadway protection in contiguous seams was put forward. The technical principle of split-layer roof cutting and pressure relief for roadway protection was analyzed, and the calculation formula of split - layer roof cutting height in contiguous seams was deduced. The key parameters of split-layer roof cutting were given, and the effect of roof cutting and pressure relief for roadway protection was studied. The results show that the length of cantilever beam can be shortened by adjusting the fracture position of split-layer roof cutting actively, and the energy transfer of backward rock is reduced due to the buffering action of goaf and intercalation, which effectively protects the stability of surrounding rock of lower roadway. In addition, the influence of caved refuse of roof on the filling effect of the local level airside and the lower level airside and the caved rock between layers should be considered in the determination of the height of split-layer roof cutting. The field industrial test shows that the floor heave of dynamic pressure roadway decreases from 3. 0 m to about 0. 5 m after split-layer roof cutting, with a decrease of 83%.