陕西煤炭

【目的及方法】为了探究离层空间从产生到发展直至压实过程中的发育规律，以准东二矿1101工作面为研究对象，基于组合梁原理对离层可能发育的层位做出预测，结合离散元数值模拟软件UDEC对大埋深综放开采条件下覆岩离层发育特征展开研究。【结果及结论】结果表明，离层的发育层位与工作面推进距离成正比，离层发育层位随工作面推进自下而上发育。模拟结果显示在关键层1及主关键层底部产生明显的闭合“腔体”离层，关键层1底部的低位离层发育周期短，离层裂隙从产生至发育过程中，离层下位岩层发生破断垮落，无法形成闭合“腔体”离层；主关键层底部的离层则发育周期较长，随着工作面的推进，关键层1与关键层2形成的组合结构发生沉降，主关键层底部产生离层裂隙。离层裂隙在下位岩层沉降过程中持续发育，直至主关键层发生弯曲下沉，离层发育速度开始变缓，当主关键层下沉速度大于离层下位岩层下沉速度时，离层空间开始被压缩，最终离层被压实。

To investigate the development laws of separation space from initiation, development to compaction, the 1101 working face of Zhundong No. 2 Mine was taken as the research object. Based on the composite beam theory, the potential horizons where separation may develop were predicted, and the development characteristics of overburden separation under large mining depth and fully mechanized top-coal caving conditions were studied using the discrete element numerical simulation software UDEC. The results show that the development horizon of separation is proportional to the advancing distance of the working face, and the separation develops from lower to higher horizons as the face advances. Simulation results reveal that distinct closed "cavity" separations appear beneath key stratum 1 and the primary key stratum. The lowlevel separation beneath key stratum 1 has a short development cycle; during the process from fracture initiation to development, the underlying strata break and collapse, preventing the formation of a closed "cavity" separation. In contrast,the separation beneath the primary key stratum exhibits a longer development cycle. As the working face advances, the composite structure formed by key stratum 1 and key stratum 2 settles, generating separation fractures beneath the primary key stratum. These fractures continue to develop during the subsidence of the lower strata until the primary key stratum begins to bend and subside, at which point the separation development rate slows down. When the subsidence velocity of the primary key stratum exceeds that of the strata below the separation, the separation space starts to be compressed and is ultimately compacted.