【摘要】 针对榆神矿区坚硬特厚煤层综放开采所面临的顶煤悬顶距长、冒放性差、采出率低和采放不协调等问题,探讨了机采割煤高度6. 0 m以上的超大采高综放开采可行性和必要性,分析超大采高综放开采支架-围岩耦合关系,在支架-围岩强度、刚度和稳定性耦合的基础上,提出超大采高综放开采支架-围岩结构耦合理论。从液压支架与围岩相互作用机理角度,阐释了支架-围岩支护系统"小结构"初次耦合主动支撑和"大结构"二次耦合被动承载概念和理论,分析了围岩"大、小结构"耦合对工作面围岩支护效果和适应性的影响,指出综采放顶煤液压支架结构设计除需满足"小结构"支护系统适应"大结构"周期性破断失稳形成的强动载矿压外,还需考虑液压支架结构(特别是放煤机构结构)对顶煤冒放运移规律和支架载荷演化过程的影响,通过支架结构与顶煤冒放结构耦合实现顶煤顺利放出,提高顶煤采出率。采用理论分析、相似模拟、数值模拟和现场调研等研究方法,分析了坚硬顶煤冒落和放出结构以及冒放过程的成拱机理,讨论了液压支架结构高度对矿山压力显现强度、顶煤冒放结构和资源采出率的影响,研究了放煤机构结构对顶煤成拱结构的影响,以及放煤机构结构对顶煤的二次破碎作用,提出了强力放煤机构结构改进和优化策略,并对破煤机理和效果进行探讨,以期为相似坚硬特厚煤层综放开采支架-围岩耦合提拱理论指导和借鉴。更多还原

【Abstract】 Aimed at the challenges,such as long overhanging top-coal,poor cavability,low recovery and incoordination of coal cutting and coal drawing,faced in longwall top coal caving( LTCC) mining with extra-thick and hard coal seam in Yushen mining area,the authors discussed the feasibility and necessity of LTCC operation with super-large cutting height( greater than 6.0 m),and analyzed the coupling between hydraulic roof support and surrounding rock.Based on the coupling of strength,stiffness and stability of support-surrounding rock,a structure coupling theory of support-surrounding rock in LTCC mining with super-large mining height is put forward. The concepts and theories of "small structure"primary coupling,active supporting,and "large structure"secondary coupling,passive bearing,in the support system of hydraulic supports and the surrounding rock are explained from the perspective of the interaction mechanism between them.The authors analyzed the influence of "large and small structure"coupling of surrounding rock on the supporting effect and adaptability.It is pointed out that the structural design of hydraulic support used in LTCC not only needs to meet the requirement of adaptation of small structure supporting system to the strong dynamic load caused by periodic failure and instability of large structure,but also needs to consider the influence of the structure of hydraulic support( especially the structure of coal drawing mechanism) on the caving and migration law of hard topcoal,as well as the load evolution process of the support.The coupling between the structure of hydraulic support and the structure of caved top-coal can realize a smooth drawing of top coal and improve the recovery rate of top-coal.The methods of theoretical analysis,similarity simulation,numerical simulation and field investigation are adopted to analyze the caving and drawing structure of hard top coal and the arching effect during the coal drawing process.The influence of the structure height of hydraulic support on the caving structure and resource recovery rate of the top coal is discussed.The effect of caving mechanism structure on the arch structure of top coal and the secondary crushing effect of caving mechanism structure on top coal are studied. The structural improvement and optimization strategies of the strong coal drawing mechanism are put forward,and the mechanism and effect of coal breaking are discussed.This paper would provide guidance and reference for the coupling theory of hydraulic roof support and surrounding rock in similar hard and extremely thick coal seam.更多还原