孤岛工作面长度对下伏大巷稳定性影响研究

以开滦矿区某矿8#孤岛煤柱回采为工程背景，针对孤岛工作面长度对底板垂直应力的分布影响及下伏大巷围岩稳定性问题展开研究。采用理论分析和数值模拟相结合的手段，建立了孤岛工作面在倾向方向上的底板受力模型，采用半无限体空间理论，推导出底板垂直应力计算公式，将该孤岛工作面实际地质参数带入公式，得出了孤岛工作面长度与底板应力之间的函数曲线。研究表明:当该孤岛工作面长60 m时，对下方-480 m水平大巷产生的垂直应力最小。通过FLAC 3D数值模拟方法验证了8#孤岛工作面合理尺寸（60 m)比实际孤岛工作面长度（100 m)对下方水平大巷的采动影响小，便于维护。

Study on influence of length of isolated island working face on stability of underlying main roadway

Taking the mining of 8# isolated island coal pillar in a certain coal mine of Kailuan mining area as the engineering background, the influence of the length of isolated island working face on the distribution of vertical stress at the floor was studied, as well as the stability of surrounding rock in the underlying main roadway. A model of floor force in the inclination direction of isolated island working face was established by using the combined method of theoretical analysis and numerical simulation, and a formula for calculating the vertical stress of the floor was deduced by using the theory of semi-infinite body space. The actual geological parameters of this isolated island working face were input into the formula, and the function curve between the length of isolated island working face and the floor stress was obtained. The results showed that when the length of isolated island working face was 60 m, the vertical stress produced on the underlying -480 m horizontal main roadway was the smallest. Through the numerical simulation of FLAC 3D, it was verified that the mining influence on the underlying horizontal main roadway with the reasonable size (60 m) of 8# isolated island working face was smaller than that with the actual length (100 m), which was easy to maintain.