长壁开采煤柱支承压力及塑性区分布规律

为了研究长壁开采采面面间煤柱支承压力与塑性区分布规律,采用理论推导、数值模拟、现场监测的方法,通过考虑采空区上覆岩土体自重荷载作用下煤岩体的成拱效应,推导了临近采空区侧煤柱顶部支承压力计算式,基于所得支承压力对煤柱进行弹塑性分析,建立临界状态下煤柱弹塑性微分方程并求解,给出了煤柱塑性区计算式.根据玉华煤矿2410工作面工程地质条件,采用ANSYS对不同采深(500～600 m)与采空区宽度(160～280 m)的煤柱塑性区分布规律进行模拟研究,将数值模拟与理论所揭示的规律进行对比,研究理论适应范围;为验证理论的可靠性,进一步对玉华煤矿2410工作面回风巷道煤柱塑性区进行监测,并将监测结果与理论计算结果对比.结果表明:数值模拟揭示的煤柱塑性区分布规律与理论反映出的规律一致,同时发现在大采宽条件下计算出的煤柱最大塑性区宽度与模拟结果吻合度较高.现场监测结果进一步验证了计算理论的可靠性.研究结果给出了大采宽下长壁开采时综采工作面面间煤柱顶部支承压力分布以及最大塑性区宽度计算式,可为煤柱设计提供依据.

GU Shuancheng,YANG Chaofan,WANG Pan,NIU Hongxin

In order to study the distribution law of supporting pressure and plastic zone of coal pillar between mining face of longwall mining, Considered the arching effect of under deadweight load of overlying rock and soil in goaf,the calculation formula of supporting pressure of coal pillar is deduced by theoretical derivation, numerical simulation and field monitoring. The plastic zone distribution of coal pillar with different mining depth (500~600 m) and goaf width (160~280 m) is simulated by ANSYS according to the engineering geological conditions of 2410 working face of Yuhua Coal Mine. In order to verify the reliability of the theory, the plastic zone of return air roadway in 2410 working face of Yuhua Coal Mine is further monitored, and the monitoring results are compared with the theoretical calculation results. The results show that the distribution law of plastic zone of coal pillar revealed by numerical simulation is consistent with that reflected by the theory in this paper. At the same time, it is found that the maximum plastic zone width of coal pillar calculated under the condition of large mining width is highly compatible with the simulation results. The field monitoring results further verify the reliability of the calculation theory. The results show that the pressure distribution and the maximum plastic zone width of the top of the coal pillar are calculated for the design of the coal pillar.