Poor stability of the quarry roof is particularly prominent in close coal seam group mining. To address this challenge, the stability of the quarry roof under repeated mining disturbance was investigated using a combination of indoor tests, similar simulations and numerical simulations. The study obtained that: under the influence of two repeated mining disturbances, the 17# coal roof fissures are especially developed, and the rock seam strength is lower and the deformation is increased. Compared with the single seam mining roof, the direct roof of the close coal seam group is more easily destroyed under the same roof pressure; the thickness of 16# coal seam is small, the basic roof breaks regularly with the forward advance of the working face, forming a stable “The roof will go through the process” of “stability-destabilization-restabilization”; while the thickness of 17# coal seam is larger, the broken rock of the roof cannot be hinged due to the large rotation angle. During the mining process, the overlying rock above the 17101 mining face will form a “cantilever beam” structure due to the direct collapse of the basic top rock. This formation leads to a significant stress concentration on the coal wall and top plate in front of the working face of the lower coal seam. The repeated mining of the lower coal seam causes the overlying rock to act as a bedding layer, moderating the mine pressure. Consequently, the mining of the upper coal seam results in a reduction of cyclic pressure steps during the repeated mining of the lower coal seam.

在近距离煤层群开采中，采石场顶板稳定性差的问题尤为突出。为了应对这一挑战，通过室内测试、类似模拟和数值模拟相结合的方式，研究了采石场顶板在重复采矿扰动下的稳定性。研究得出：在两次重复开采扰动的影响下，17#煤顶板裂隙特别发育，岩层强度降低，变形增大。与单煤层开采顶板相比，封闭煤层群直接顶板在相同顶板压力下更容易被破坏； 16#煤层厚度较小，随着工作面向前推进，基础顶板有规律地破裂，形成“稳定-失稳-再稳定”的稳定“顶板经历过程”；而17#煤层厚度较大，由于回转角度较大，顶板碎岩无法铰接。在开采过程中，17101工作面上方的覆岩将因基性顶岩的直接塌陷而形成“悬臂梁”结构。这种形成导致下煤层工作面前面的煤壁和顶板应力显着集中。下部煤层的重复开采导致上覆岩石充当层理层，缓解矿压。因此，上部煤层的开采导致下部煤层重复开采期间循环压力阶跃的减少。