Roof instability is a pervasive hazard that may cause injuries and fatalities in underground coal mines. Variations in air humidity and the duration of roof exposure are known to significantly influence the stability of shale roof strata. Moisture-sensitive shales progressively deteriorate over time due to humidity-interaction and matrix swelling which can trigger skin failure and roof falls. Quantifying the evolution of dynamic mechanical and petrophysical properties of the shale roof requires a comprehensive understanding of the retention behavior of multiphase fluids in the shale and of the induced alterations associated with air-water-shale/coal interactions. This study presents a mechanism-based framework for modeling the integrative deformation and failure behaviors of the rock structure, shale roof and coal pillar—and integrates the coupled effects of water vapor flow, elastic deformation, and damage. A Time-Dependent Rock-Fluid-Geomechanics Model (TD-RFG Model) was developed to evaluate the time-dependent rock structure dynamics. The interactions across the elastic deformation field, the transient fluid transport field and the discontinuous damage field are analyzed and modeled using TD-RFG. The established TD-RFG platform provides a pathway for multi-field and time-dependent rock structure stability assessment. A case study of shaly roof stability in an Illinois Basin coal mine and an analysis of it are presented. In the analysis we investigate the time- and location-dependent propagation of rock fractures that create connected channels that allow for rapid water penetration. The analysis indicates that, because of damage-induced increases in permeabilities, moisture transport is facilitated and so seasonal relative humidity variations at the mine opening are quickly reflected at interior locations in the shale roof, coal pillars and ground floor. The results of the modeling can ultimately provide the approach and data for quantifying and evaluating the water retention behavior and suction potential in an unsaturated air-water-shale/coal system and define strategies for ground control.

屋顶不稳定是一种普遍存在的危害，可能会导致地下煤矿的人员伤亡。众所周知，空气湿度的变化和顶板暴露时间会显着影响页岩顶板地层的稳定性。由于湿度相互作用和基质膨胀，水分敏感性页岩会随着时间的推移逐渐恶化，这会引发表皮破坏和顶板倒塌。量化页岩顶板的动态力学和岩石物理特性的演变需要全面了解页岩中多相流体的滞留行为以及与空气-水-页岩/煤相互作用相关的诱发变化。本研究提出了一种基于机制的框架，用于模拟岩石结构的综合变形和破坏行为，, 和损坏。开发了瞬态岩石流体地质力学模型（TD-RFG 模型）来评估瞬态岩石结构动力学。使用 TD-RFG 对弹性变形场、瞬态流体传输场和不连续损伤场的相互作用进行分析和建模。已建立的 TD-RFG 平台为多场和时间相关的岩石结构稳定性评估提供了途径。介绍了伊利诺伊州盆地煤矿页岩顶板稳定性的案例研究及其分析。在分析中，我们研究了岩石裂缝的时间和位置相关的传播创建连接的通道，允许快速渗水。分析表明，由于损坏引起的渗透率增加，促进了水分输送，因此矿井开口处的季节性相对湿度变化很快反映在页岩顶板、煤柱和底层的内部位置。建模结果最终可以为量化和评估非饱和空气-水-页岩/煤系统中的保水行为和吸力潜力提供方法和数据，并定义地面控制策略。