浅埋煤层切顶成巷覆岩运动及荷载传递规律研究

The law of the overlying strata movement and its load transfer are not only significant compared with the traditional gob-side entry retaining, but also have have an important influence on the stability of the surrounding rock along the goaf in shallow coal seam the during the gob-side entry retaining formed by roof cut and pressure releasing. Therefore, it is necessary to study the law of overlying strata movement and its load transfer during the gob-side entry retaining. Based on the typical conditions of the shallow thick coal seam with the thin bedrock, the overlying strata movement law under the influence of the roof cut will be revealed in the shallow-buried thick coal seam during the gob-side entry retaining by means of model experiment, numerical simulation and theoretical analysis and so on. And it will be ascertained to the equilibrium mechanism and conditions of the stope overlying strata under the influence of roof cut. Then, through the analysis of the three-dimensional stress distribution characteristics and evolution law, the mechanical relationship between the overlying strata movement and the stope stress distribution under the influence of the roof cut is established. Meanwhile, the influence of overlying strata movement on stress distribution is revealed along the gob roadway and the working face. Based on the comprehensive analysis of the distribution and evolution of overburden displacement field, temperature field and stress field during the gob-side entry retaining formed by roof cut and pressure releasing in shallow coal seam, the evolution model of load transfer path and strength, and the structure mechanical model of the load transfer in the typical regional of the dynamic pressure zone are established. And the load transfer law of overburden strata is revealed during the gob-side entry retaining. The study in this project will further enrich and perfect the theory of coal mining and provide an important theoretical basis for the wide spread and application of the technology of the gob-side entry retaining formed by roof cut and pressure releasing under the condition of shallow coal seam.

切顶成巷中覆岩运动及荷载传递规律不仅与传统留巷方法相比差异显著，且对浅埋煤层沿空巷道围岩稳定性具有重要影响，然而，目前切顶成巷中的覆岩运动及荷载传递规律并不清楚。因此，切顶成巷覆岩运动及荷载传递规律的深入研究十分必要。本项目拟采用模型实验、数值模拟及理论分析等手段，针对浅埋薄基岩厚煤层的典型条件，揭示切顶成巷覆岩运动规律，确定切顶影响下采场覆岩位态平衡机理及条件。通过分析采场三维应力分布特征及演化规律，建立切顶影响下覆岩运动与采场应力分布之间的力学联系，揭示覆岩运动对采场应力分布的影响规律。通过综合分析切顶成巷过程中覆岩位移场、温度场、应力场的分布及演化规律，建立切顶成巷覆岩荷载传递路径和强度的演化模式及动压区内典型区域荷载传递的结构力学模型，揭示成巷过程中覆岩荷载传递规律。本项目的研究将进一步丰富和完善煤矿开采理论，为切顶成巷技术在浅埋煤层条件下的广泛推广应用提供重要的理论依据。

项目通过对浅埋煤层切顶成巷覆岩运动及荷载传递规律的深入研究，揭示了浅埋煤层切顶成巷过程中覆岩运动及巷道围岩应力演化规律，阐明了浅埋煤层切顶成巷过程中巷道围岩结构断裂机制，建立了浅埋煤层切顶成巷过程中巷道围岩结构变形力学模型，揭示了浅埋薄基岩厚煤层切顶成巷过程中沿空巷道顶板与沿空侧采空区覆岩断裂之间的相互联系，揭示了浅埋薄基岩厚煤层切顶成巷过程中覆岩荷载传递规律，在此基础上提出了浅埋薄基岩厚煤层切顶成巷沿空巷道围岩稳定性控制对策，对比分析了不同支护形式下巷道围岩应力及变形规律，提出了提出了“恒阻锚索+钢锚杆+液压支柱+波形边钢梁+ U型钢”的协同支护方案，结果表明该支护形式可大幅提高采动应力影响下沿空巷道围岩的完整性和承载能力，研究成果将为相似条件下切顶成巷无煤柱开采技术的推广应用提供有益参考。