基于FLAC3D的后安煤矿110203综采工作面矿压分布规律数值模拟及沉陷预测研究

Numerical Simulation of Strata Pressure Distribution Law and Subsidence Prediction for the 110203 Fully-Mechanized Mining Face in Hou’an Coal Mine Based on FLAC3D

摘要: 为研究山西朔州后安煤矿110203综采工作面采动引起的矿压分布规律及地表沉陷特征，本研究结合井下采样与实验室实测获得的煤岩体力学参数，采用FLAC3D数值模拟软件建立了三维地质力学模型。模拟分析了顶板初次来压(步距20 m)与周期来压(步距30 m)两种典型工况下，工作面前方围岩的应力场、塑性区及卸压区演化规律。研究结果表明：① 煤壁前方依次形成卸压区、应力集中区和原岩应力区，初次来压与周期来压的卸压区宽度分别为14 m和15 m，应力峰值位置分别位于煤壁前方16 m和17 m处，周期来压的应力集中系数更高，矿压显现更为剧烈；② 周期来压时顶板及煤壁塑性区范围显著扩大，老顶参与来压，增加了围岩失稳风险；③ 敏感性分析揭示煤体内聚力和内摩擦角是影响卸压区与塑性区范围的最敏感参数。本研究结论为工作面的支护优化、卸压瓦斯抽采区域的确定以及地表沉陷范围的科学圈定与复垦提供了重要的理论依据和数据支持。

Abstract: To investigate the mining pressure distribution law and surface subsidence characteristics induced by mining activities in the 110203 fully-mechanized mining face of Hou’an Coal Mine, Shuozhou, Shanxi Province, this study established a 3D geomechanical model using the FLAC3D numerical simulation software. The model was constructed based on the mechanical parameters of coal and rock masses obtained from underground sampling and laboratory measurements. Simulations were conducted to analyze the evolution laws of the stress field, plastic zone, and pressure relief zone in the surrounding rock ahead of the working face under two typical working conditions: initial roof weighting (with a weighting interval of 20 m) and periodic roof weighting (with a weighting interval of 30 m). Research results indicate that ① a stress-relief zone, a stress concentration zone, and an original rock stress zone are sequentially formed in front of the coal wall. The widths of the stress-relief zones during the first weighting and periodic weighting are 14 m and 15 m, respectively; the locations of the stress peaks are 16 m and 17 m ahead of the coal wall, respectively. The stress concentration coefficient during periodic weighting is higher, leading to more intense strata behavior. ② During periodic weighting, the plastic zone ranges of the roof and coal wall expand significantly, and the main roof participates in the weighting process, which increases the risk of surrounding rock instability. ③ Sensitivity analysis reveals that the cohesion and internal friction angle of coal are the most sensitive parameters affecting the ranges of the stress-relief zone and plastic zone. The conclusions of this study provide an important theoretical basis and data support for the optimization of working face support, the determination of pressure relief gas drainage areas, as well as the scientific demarcation and reclamation of surface subsidence ranges.