深埋中厚煤层切顶成巷围岩应力演化规律试验研究

The difficulty of surrounding rock stability controlling has become the bottleneck of the development of gob-side entry retaining technology in deep gob-side roadway. In view of the key scientific problems, which belong to surrounding rock stability controlling of gob-side entry retaining formed by roof cutting in deep medium-thick coal seam, this project systematically studies the spatio-temporal evolution law of stress by means of laboratory experiments, numerical simulation and theoretical analysis, and so on. By summing up characteristics of the surrounding rock of roof-cutting roadway in the whole period deformation, the influence mechanism between the key parameters of roof-cutting roadway and the stability of surrounding rock is analyzed, and the structural equilibrium characteristics and coupling mechanism of "roof-cutting short arm beam-goaf gangue-solid surrounding rock" are explored. Based on the results of three-dimensional physical model test and numerical simulation, the fracture location and movement characteristics of the basic roof are determined, the mechanism of coordinated deformation between the big structure of basic roof and the small structure of surrounding rock is analyzed, and the deformation characteristics of the surrounding rock structure and the spatio-temporal evolution law of the stress field in the whole process of "mining-retaining-using" of the cutting roadway are mastered. The mechanical model of stability control of surrounding rock in roof-cutting roadway is established. The mechanism of stability control of surrounding rock in roof-cutting roadway is revealed. The comprehensive evaluation system of stability control of surrounding rock in roof-cutting roadway in deep medium-thick seam is established, which provides more scientific theoretical basis for stability control design, monitoring and early warning of surrounding rock in roof-cutting roadway in deep medium-thick coal seam.

深埋沿空巷道围岩稳定性控制难题成为了制约沿空留巷技术发展的瓶颈。为此，本项目针对深埋中厚煤层切顶成巷围岩稳定性控制的关键科学问题，采用室内实验、理论分析及数值模拟等研究方法，系统开展深埋中厚煤层切顶成巷围岩应力时空演化规律的研究。通过总结切顶成巷围岩全周期变形特征，分析切顶成巷关键参数与围岩稳定性之间的影响机制，探究“切顶短臂梁-采空区矸石-实体围岩”结构平衡特征及其耦合作用机制；综合三维物理模型试验和数值模拟分析结果，确定切缝基本顶的断裂位置及运动特征，研究切缝基本顶大结构与围岩小结构协调变形机理，掌握切顶成巷“采-留-用”全过程围岩结构变形特征及应力场时空演化规律；建立切顶成巷围岩稳定性控制力学模型，揭示切顶成巷围岩稳定性控制机理，建立深埋中厚煤层切顶成巷围岩稳定性控制综合评价体系。研究可为深埋中厚煤层切顶成巷围岩稳定性控制设计及监测预警等提供理论支持和科学依据。

深部煤炭资源是未来我国能源安全的重要保障，确保深部回采巷道稳定性是保障深部煤炭资源安全高效开采的关键。为此，本项目针对深埋中厚煤层切顶成巷围岩稳定性控制的关键科学问题，采用室内实验、理论分析及数值模拟等研究方法，系统开展了深埋中厚煤层切顶成巷围岩应力场时空演化规律的研究，总结了影响切顶成巷围岩稳定性因素，研究了自成巷道围岩全周期变形特征；分析了切顶成巷关键参数与围岩稳定性之间的影响规律，探究了“切顶短臂梁-采空区矸石-实体围岩”结构平衡特征及其耦合作用机制；综合物理模型试验和数值模拟分析结果，确定切缝基本顶的断裂位置及运动特征，掌握切顶成巷“采-留-用”全过程围岩结构变形特征及应力场时空演化规律；建立切顶成巷围岩稳定性控制力学模型，揭示切顶成巷围岩稳定性控制机理，建立深埋中厚煤层切顶成巷围岩稳定性控制综合评价体系。研究可为深埋中厚煤层切顶成巷围岩稳定性控制设计提供理论支持和科学依据；将上述研究成果应用于现场实际工程，取得了良好的应用效果。