巨厚火成岩下采动裂隙场与瓦斯流动场耦合规律研究

The coupling laws between fissure field and gas flow field under an extremely thick igneous rock

为考察巨厚火成岩下远程下保护层开采覆岩采动裂隙场与瓦斯流动场耦合规律,通过采用理论分析、相似模拟试验、数值模拟实验及现场观测的方法,分析了覆岩垮落变形和裂隙发育规律,研究了巨厚火成岩下瓦斯储运规律。结果表明:巨厚火成岩控制着其上覆岩层的全部运动,弯曲带内存在裂隙与离层长期不闭合的区域,即离层区;弯曲带内离层区存在大量离层裂隙和少数穿层裂隙,其中裂隙成为瓦斯运移的通道,离层成为瓦斯的富集区;巨厚火成岩下断裂带与离层区内气体运移与煤岩体变形之间存在着复杂的相互作用,它是渗流场、浓度场和裂隙场(包括离层)之间耦合的一个动态平衡体系。

For researching the coupling laws between fissure field and gas flow field under an extremely thick igneous rock during distant lower protective layer mining,based on theoretical analysis,similarity simulation test,numerical simulation analysis and field observation,analyzed rock collapse and fraction evolution laws of overlying strata,gas storage and migration.The results show that the extremely thick igneous rock controll movement of overlying strata,and separation zone is formed in the bending zone.A large number of separations and a few fractures exist in the separation zone,and separations and fractures are not close for a long time.The fractures become the channels of gas migration and separations become the enrichment areas of pressure relief gas.A complex interaction appeares between gas migration and coal-rock mass deformation in the fractured and the bending zones,which build the dynamic equilibrium system among seepage field,concentration field and fracture field.