近距离煤层大采高综放开采顶煤冒放性分析

Cavability Analysis of Top-coal at Close Coal Seams Full Mechanized Caving Face with Large Height

针对近距离煤层大采高综放顶煤冒放性这一核心问题,理论分析了近距煤层上位煤层未采、上位煤层已采煤体的损伤力学特性,模拟了2种情况下顶煤体的支承压力分布规律、顶煤体裂隙发育及顶煤体破断特征。研究表明:顶煤体的冒放性可用顶煤体损伤程度表示,与顶煤体的原始裂隙和采动支承压力有关;与上位煤层未采相比,上位煤层开采一方面增加了下位煤层顶煤体的原始裂隙,另一方面加大了下位顶煤体所承受的支承压力,从而提高了顶煤体的冒放性。

Aiming at the core problem of top coal cavability at full- mechanized caving face with large mining height in close coal seams,the damage mechanic properties of mined and un- mined at upper coal seam were analyzed through theoretical analysis,the distribution of abutment pressure and the fractures development and the breakage of top coal were simulated by numerical model. The result shows that the top coal cavability which was indicated by the damage degree of top coal was affected by the original fissures and abutment,compared with the un- mined upper coal,the mining of the upper seam increased the original fissures of lower seam,and increased the abutment pressure of lower coal seam,and then increased the cavability of the top coal.