深部充填开采覆岩移动及应力转移规律研究

    Research on movement and stress transfer law of overburden rock in deep filling mining

    • 摘要: 随着浅部煤矿资源逐渐枯竭,人类不得不向深部开发煤炭资源。然而,随着开采深度的增加,深部开采环境也发生了根本性变化,主要表现为“三高一扰动”。深部充填开采覆岩移动特征及矿压显现规律与浅部充填开采具有明显差异性。采用电液伺服万能试验系统和加载钢桶装置,测试了矸石试样侧限轴向压缩特性;采用X射线荧光法分析了矸石充填材料的化学成分;选取新巨龙煤矿1303N-1#工作面为工程案例,测定了工作面煤岩层物理力学参数;采用FLAC3D数值模拟软件,建立了1303N-1#工作面三维充填开采数值模型,分析了不同充实率条件下工作面覆岩垂直应力、应变能、垂直位移和塑性区的分布规律;设计并监测了1303N-1#工作面顶板位移、充填体应力、充填体变形。数值结果显示:随着充实率的增加,工作面超前支承应力降低、顶板变形量减小、塑性区范围降低;在充实率40%时,基本顶的垂直应力较高,且应力集中在煤壁周围,塑性区扩展至基本顶上方9 m位置,基本顶发生破断;在充实率80%和90%时,基本顶的支承应力峰值降幅46%,直接顶塑性区基本不发育或者发育不明显,基本顶仅发生弯曲下沉。现场1303N-1#工作面监测结果表明:采空区充实率为85.4%,顶板最大垂直位移量为438 mm,充填体内部应力最大值达到14.2 MPa,充填开采有效降低了覆岩的变形与应力集中。

       

      Abstract: As the shallow coal resources gradually deplete, humans have to develop deeper coal resources. However, with the increase in mining depth, the deep mining environment undergoes fundamental changes, primarily characterized by “three highs and one disturbance” (high temperature, high pressure, high gas content, and disturbance). The overburden movement characteristics and the manifestation laws of mining-induced pressure in deep filling mining exhibit significant differences compared to shallow filling mining. In this study, the axial compression characteristics of gangue samples were tested using an electro-hydraulic servo universal testing system and a loading steel barrel device. The chemical composition of the gangue filling material was analyzed by X-ray fluorescence (XRF). The 1303N-1# working face of Xinjulong Coal Mine was selected as the engineering case, and the physical and mechanical parameters of the coal-rock layers in the working face were measured. Using FLAC3D numerical simulation software, a three-dimensional filling mining model of 1303N-1# working face was established to analyze the distribution of vertical stress, strain energy, vertical displacement, and plastic zone under different filling rates. The displacement of the roof, the stress of the filling body, and the deformation of the filling body in 1303N-1# working face were designed and monitored. The numerical results show that with the increase in the filling rate, the advanced support stress of the working face decreases, roof deformation reduces, and the plastic zone shrinks. At the filling rate of 40%, the vertical stress of the immediate roof is higher, with stress concentrated around the coal wall, and the plastic zone extends to 9 meters above the immediate roof, causing rupture. At filling rates of 80% and 90%, the peak value of the support stress of the immediate roof decreases by 46%, and the plastic zone of the immediate roof is either undeveloped or insignificant. The immediate roof only experiences bending and subsidence. Monitoring results in 1303N-1# working face indicate that the filling rate of the goaf is 85.4%, with the maximum vertical displacement of the roof reaching 438 mm, and the maximum internal stress of the filling body reaching 14.2 MPa. Filling mining effectively reduces the deformation and stress concentration of the overburden. The findings provide theoretical support and engineering reference for deep filling mining.

       

    /

    返回文章
    返回