冲击地压矿井不同采动强度下的开采扰动特征及其产能

Research on mining disturbance characteristics and productivity of rock burst mines under different mining intensities

  • 摘要: 开采扰动是导致深部煤岩体发生变形、冲击、失稳的根本原因,而开采扰动特征与采动强度密切相关。进入深部开采后,冲击地压矿井数量随采动强度的增大而不断增多,研究冲击地压矿井不同采动强度下的开采扰动特征,进而根据采动煤岩力学响应特征确定合理的采动强度对冲击地压防控具有重要意义。以典型冲击地压矿区彬长矿区为例,利用数值模拟及理论分析根据不同采动强度下煤岩采动应力、能量释放及覆岩垮落结构特征,分析了不同推进速度、不同采厚下的开采扰动特征,评估了不同采动强度时采动煤体的冲击危险性,并探讨了开采扰动特征在矿井产能调控及开采方法优选等方面的应用。研究结果表明:① 煤炭年产量与冲击地压矿井数量呈正比例关系,且深部矿井发生冲击地压的可能性明显高于浅部矿井;② 整层开采的顶底板应力、超前支承压力及冲击危险性均大于分层开采,且前者存在明显的应变能峰值前移现象;③ 工作面采厚增加将会引起关键块的回转角及断裂度增大,提高了滑落失稳及回转失稳的可能性,推进速度加快将会提高回转失稳的可能性,更易诱发上覆岩层破断及能量大量释放,从而提高冲击危险性;④ 揭示了不同采动强度下的深埋煤层工作面的开采扰动特征,提出了根据不同采动强度下的开采扰动特征反向确定矿井合理的采动强度,进而确定矿井产能的方法,并基于开采扰动特征优选了孟村煤矿开采方法,为指导矿井冲击地压灾害防治提供了科学依据。

     

    Abstract: Mining disturbance is the root cause of the deformation, rock burst and instability of deep coal and rock mass, and the characteristics of mining disturbance are closely related to the mining intensity. After entering deep mining, the number of rock burst mines is increasing with the increase of mining intensity. Studying the mining disturbance characteristics under different mining intensities in rock burst mines, and then determining the reasonable mining intensity according to the mechanical response characteristics of mining coal ars of great significance to the prevention and control of rock burst. Taking the Binchang mining area in the typical rock burst mining area as an example,the methods of numerical simulation and theoretical analysis are used to analyze the characteristics of coal and rock mining stress, energy release and overburden caving structure under different mining intensities. The mining disturbance characteristics under different advance speeds of working face and different mining thicknesses are analyzed, the rock burst risk of mining coal body under different mining intensities is evaluated, and the application of mining disturbance characteristics in mine productivity control and mining method optimization is discussed. The results show that ① The annual coal output is in direct proportion to the number of rock burst mines, and the probability of rock burst in deep mines is significantly higher than in that shallow mines.②The top and floor stress, advanced support pressure and rock burst hazard of whole coal seam mining are all greater than those of slicing mining, and the former has obvious peak strain energy forward movement.③The mining thickness of the working face is increased that the rotation angle and fracture degree of the key block is increased, and the possibility of sliding and rotation instability is improved. The advanced speed is increased that the possibility of rotation instability is increased, and it will be easier to induce the breaking of the overlying strata and the release of large amounts of energy, thereby increasing the rock burst hazard.④The mining disturbance characteristics under different mining intensities is revealed. A method to reversely determine the reasonable mining intensity and then determine the mine productivity based on the mining disturbance characteristics under different mining intensities is proposed. Based on the characteristics of mining disturbance, the mining method of the Mengcun coal mine is optimized. It provides a scientific basis for guiding the prevention and control of rock burst disasters in mines.

     

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