【目的】现有的关于煤层采动揭露底板隐伏断层突水试验研究成果,仅考虑了煤层下伏单一承压含水层条件,需研究煤层底板多承压含水层条件下隐伏断层活化导水特征。【方法】通过室内相似物理模拟方式,对煤层底板双层承压含水层条件下,采动过程隐伏充水通道在不同深度上的应力和孔隙水压力演变规律进行了分析。【结果】结果表明:利用自主设计的煤层底板隐伏断层突水试验系统,可以相对合理地模拟两层承压含水层条件下不同深度上的断层活化导水规律;浅部比深部断层带的应力增量、孔隙水压力增量变化程度相对更高,孔隙水压力变化时间均滞后于应力变化时间;临近开采结束阶段,浅部和深部断层带孔隙水压力增量的上升趋势,表明断层带向采空区卸荷促进了渗流导升,断层带存在滞后突水的可能性,浅部较深部断层带的滞后突水风险相对更高。应力扰动程度整体上随深度增加而衰减,浅部相对深部断层带更易活化,持续不断的扰动将使浅部和深部含水层发生水力联系,深部承压水可通过隐伏断层补给浅部承压水,承压水通过断层带导升过程存在着显著的水头压力损耗。【结论】试验结果可为底板多承压含水层条件下隐伏断层活化导水模式分析提供理论和工程实际参考。

【Purposes】The existing researches on mining induced water inrush through concealed faults underlying coal seam floor only consider the condition of single confined aquifer under coal seam floor.  The activation characteristics of water inrush through concealed faults under the condition of two layer confined aquifers need to be studied.  【Methods】The mining stress and pore pressure evolu-tion of concealed faults at different depths during mining were analyzed by means of similar physical simulation.  【Findings】The results show that the self-designed water inrush test system can reason-ably simulate the faults’ activation and conducting law at different depths under the condition of two layer confined aquifers.  The change degree of mining stress and pore pressure increments in shallow fault zone is higher than that of deep fault zone, and the change time of pore pressure lags behind the change time of stress.  At the end of mining process, the increasing trend of pore pressure increments in shallow and deep fault zones reflects that the unloading of fault zones to the goaf promotes the devel-opment of seepage.  There is a possibility of delayed water inrush in fault zones, and the risk of de-layed water inrush in shallow fault zones is relatively higher than that of deep fault zones.  The degree of stress disturbance decreases with the increase of depth, and the shallow part is more likely to be ac-tivated than the deep fault zone.  Continuous disturbance will generate the hydraulic connection be-tween the shallow and deep aquifers, the deep confined aquifer can recharge the shallow confined aqui-fer through the concealed fault, and there is significant head pressure loss in the process of confined water inrush through fault zones.  【Conclusions】The results can provide theoretical and practical refer-ence for the analysis of concealed fault’s activation and conduction mode under the condition of multi-ple confined aquifers underlying coal floor.