【摘要】 基于对采动岩体流固耦合作用的力学响应以及底板岩体强度退化机制的认识,针对承压水体上采煤的岩体水力学模型,对底板隔水岩体的长期强度特征进行了分析,并用数值方法再现了含隐伏小断层底板在采动应力扰动和高承压水共同作用下采动裂隙形成、小断层活化、扩张、突水通道最终贯通形成的全过程。通过对损伤演化、应力场和渗流场的解读,揭示了开采扰动及水压驱动下完整底板由隔水岩层到突水通道的演化机理,对突水通道进行时空基准标定,并着重就小断层发育高度、承压水水压力大小对隔水底板的损伤演化模式及突水滞后时间的影响关系进行了分析探讨,从岩体强度退化及损伤演化机制的角度,为承压水体上采煤底板滞后突水的机理分析提供了一些新的认识。更多还原

【Abstract】 Based on the knowledge of solid-fluid coupling mechanism and strength degradation law of coal seam floor,numerical tests with FEM method are conducted to investigate the long-term characteristics of floor rock mass and the initiation of fractures,activation of faults and formation of groundwater inrush pathways based on the mechanic model for rock mass with weak faults in coal mining above the confined aquifer.With the understanding of stress,damage and seepage flow evolution,the transformation of floor rock mass from water-resisting strata to inrush pathways is clearly illuminated and the groundwater inrush pathways are calibrated.Furthermore,the influence of the height of faults and the magnitude of water pressure on the damage evolution and delayed time of groundwater inrush is studied.And some significantly meaningful guides are provided for the investigation on the mechanism and prevention of delayed groundwater inrush in practice.更多还原