高级检索

大倾角近距离煤层综采运输巷断面形状与支护参数优化

Optimization of cross-sectional shape and support parameters of headgate in fully mechanized coal seam with large dip angle and close distance

  • 摘要: 针对大倾角近距离煤层巷道在多次剧烈采动作用下,巷道围岩频繁出现非对称变形破坏致使围岩控制困难的问题,以代池坝煤矿31233运输巷为工程背景,通过理论分析、数值模拟、现场监测等综合研究方法,研究了大倾角近距离煤层开采下3种断面形状巷道围岩变形破坏机理,进一步确定并优化了最佳非对称屋顶形巷道断面形状。研究结果表明:在大倾角近距离煤层剧烈采动情况下,无论巷道断面形状如何变化,其围岩破坏形态均呈现为最大破坏深度位置朝向顶板,且由于靠近上层工作面区域内塑性区扩展应力敏感性较强,导致该区域塑性区范围和深度达到最大,但3种断面形状巷道整体围岩破坏规律和塑性区分布范围有着明显差别;与拱形巷道、斜顶直角梯形巷道不同的是,非对称屋顶形巷道可根据巷道围岩条件变化来改变左帮、右帮高度以及左坡顶、右坡顶角度,使得巷道围岩整体应力分布趋于合理化,提升围岩破坏可控性的同时提高了巷道断面利用率。据此,提出了基于巷道围岩塑性区分布的非均匀控制方法,并进行了现场工程应用,优化断面形状前后技术经济指标对比结果表明非均匀支护方式对控制围岩变形效果明显,研究结果可为同类型大倾角近距离煤层巷道断面形状选择与支护设计优化提供有效科学依据。

     

    Abstract: Aiming at the problem that the asymmetric deformation and failure of surrounding rock frequently occur, making it difficult to control the surrounding rock under the conditions of multiple intense mining actions in thecoal seam with large dip angle and close distance. Taking the headgate 31233 in Daichiba Coal Mine as the engineering background, the mechanism of surrounding rock deformation and failure in roadways with three cross-sectional shapes under thecoal seam with large dip angle and close distance was studied through theoretical analysis, numerical simulation, and on-site monitoring. The optimal asymmetric roof shaped roadway cross-sectional shape was further determined and optimized. The research results indicate that under the conditions of intense mining of steeply inclined coal seams, regardless of how the roadway cross-section changes, the form of surrounding rock failure always exhibits the maximum depth of failure towards the roof, and due to the strong stress sensitivity of the plastic zone near the upper working face area, the range and depth of the plastic zone reach a maximum, However, there are significant differences in the overall failure patterns and distribution ranges of the plastic zone among the three cross-sectional shapes. In contrast to arch roadway and inclined roof right trapezoidal roadway, the asymmetric roof shaped roadway can adjust the height of the left and right sides as well as the angles of the left and right slope tops in response to changes in surrounding rock conditions. This adjustment leads to a more rational overall stress distribution within the surrounding rock of the roadway, enhances the controllability of rock failure, and improves the utilization rate of the roadway cross-section. Based on the distribution of the plastic zone in the surrounding rock, an uneven control method is proposed, and engineering applications are conducted. The comparison of technical and economic indicators before and after optimizing the cross-section shape indicates that the uneven support method significantly improves the control over surrounding rock deformation. The research results provide an effective scientific basis for the selection of cross-sectional shapes and the optimization of support designs for similar roadways inthecoal seam with large dip angle and close distance.

     

/

返回文章
返回