高级检索

薄煤层坚硬顶板迎采对掘沿空巷道失稳机理及控制技术研究

Research on Instability Mechanisms and Control Technologies for Gob-Side Roadways in Thin Coal Seams with Hard Roof under Mining-Excavation Interaction

  • 摘要: 针对滨湖煤矿薄煤层坚硬顶板条件下迎采对掘沿空巷道围岩变形剧烈、维护困难的技术难题,本文综合运用理论分析、数值模拟与现场试验方法,深入探究了邻空侧覆岩运动特征、垮落结构形态及其诱发的巷道失稳机理,优化了切顶卸压护巷的关键技术参数并进行工程应用。研究表明:16煤上覆岩层存在两层主导性的关键层,其结构特征与力学行为控制着邻空侧岩层的运动规律与垮落结构形态,该区域侧向悬顶在其动态演化(形成、运动及垮落)过程中,对巷道围岩施加了显著的多次动载冲击与高静载应力作用,显著增大了巷道破坏失稳风险。基于最大主应力偏张量评价指标,优化确定了切顶高度为16m、切顶角度为10°,并通过现场试验进一步优化了爆破参数,确定深孔爆破间距为2m、浅孔爆破间距为1m。此外,为提高巷道围岩承载能力,采用了“锚网索带”主体支护结合“单元支架”临时补强的综合支护体系。矿压观测表明,巷道围岩变形得到有效控制,在工作面后方滞后约140m处即达到自稳状态,验证了切顶卸压护巷技术在解决薄煤层坚硬顶板沿空巷道维护难题方面的有效性。

     

    Abstract: Addressing the technical challenges of severe deformation and maintenance difficulties in gob-side roadways with retained pillars under hard roof and thin coal seam conditions during mining-excavation interaction at Binhu Coal Mine, this study employs integrated theoretical analysis, numerical simulation, and field experiments to investigate the movement characteristics of the adjacent goaf-side overlying strata, the morphology of the caving structure, and the induced roadway instability mechanism. Key parameters for roof-cutting pressure relief and roadway protection were optimized and applied in engineering practice. The research indicates that two dominant key strata exist within the overburden of the 16# coal seam. Their structural characteristics and mechanical behavior govern the movement patterns and caving structure morphology of the adjacent strata. The dynamic evolution (formation, movement, and caving) of the lateral suspended roof in this zone subjects the roadway surrounding rock to significant multiple dynamic load impacts and high static stress, substantially increasing the risk of roadway instability and failure. Using the maximum principal stress deviatoric as the evaluation indicator, the optimal roof-cutting height and angle were theoretically determined as 16m and 10°, respectively. Field tests further optimized the blasting parameters, establishing a spacing of 2m for deep boreholes and 1m for shallow boreholes. Additionally, a comprehensive support system comprising a primary "bolt-mesh-cable-belt" support combined with temporary reinforcement using "unit hydraulic props" was proposed to enhance the load-bearing capacity of the surrounding rock. Ground pressure monitoring confirmed that roadway deformation was effectively controlled, achieving a self-stabilized state approximately 140m behind the working face. This validates the effectiveness of the roof-cutting pressure relief technology in resolving the maintenance challenges of gob-side roadways under thin coal seam and hard roof conditions.

     

/

返回文章
返回