Experimental data in steeply inclined multiseam mining

Ground surface damage caused by steeply inclined coal seam mining is widely distributed in China, but there is little research on the failure process and movement mechanism of strata induced by steeply inclined multi-seam mining. In this paper, a physical model test is carried out to study the failure process and movement mechanism of overburden in steeply inclined multi-seam stepwise mining. The results show that at the initial stage, the main failure of the rock mass is the small-scale collapse at the open-off cut and the roof (stability stage of the rock mass). After the roof is exposed over a certain range, the rock mass in the downhill direction slips into the goaf and gradually destroys the interburdens of the goaf, similar to the displacement effect of dominoes (severe failure stage of the rock mass). When the structure of the goaf fails, the overburden subsides, causing extensive damage to the ground surface. The surface damage directly above the goaf is mainly caused by serious subsidence deformation, while the surface damage in the downhill direction is dominated by cracks.

我国急倾斜煤层（steeply inclined coal seam）开采引发的地表破坏分布广泛，但针对急倾斜多煤层开采（steeply inclined multi-seam mining）诱发岩层（strata）破坏过程与运动机理的研究尚少。本文通过物理模型试验（physical model test），研究急倾斜多煤层分步开采（stepwise mining）条件下覆岩（overburden）的破坏过程与运动机理。研究结果表明：初始阶段，岩体（rock mass）的主要破坏形式为开切眼（open-off cut）与顶板（roof）的小规模垮落，此时为岩体稳定阶段。当顶板暴露至一定范围后，下坡方向的岩体将滑移至采空区（goaf），并逐渐破坏采空区的层间隔层（interburdens），其位移过程类似多米诺骨牌效应，此时为岩体剧烈破坏阶段。当采空区结构失稳时，覆岩发生沉降，进而引发大范围地表破坏。采空区正上方的地表破坏主要由严重沉降变形引发，而下坡方向的地表破坏则以裂隙发育为主。