The permeability evolution of fractures in geologic media plays a pivotal role in various geo-mechanical activities, ranging from energy resources recovery to the deep geologic disposal of hazardous materials. This paper presents both laboratory and computational investigations into the evolution of fracture permeability under the influence of varying confining stress levels in a crystalline granitic rock from the Canadian Shield. Steady state permeability experiments were conducted to assess variations in fracture permeability in areas where stress conditions may significantly change due to large-scale underground excavations. A high accuracy laser scanner was used to capture the geometric features of the fracture surface, enabling the numerical simulation analysis of stress-induced hydromechanical behavior. The fracture permeability evolution was systematically investigated under both isotropic stress and deviatoric stress conditions, including four loading–unloading sequences and a series of sequentially increased deviatoric stresses. Simulations of fracture closure under increasing confining pressure and corresponding fluid flow process were performed incorporating a model constructed from fracture elevation data obtained through scanning. The results demonstrate a reduction in permeability exceeding 50% as the triaxial confining stress increases from 5 to 40 MPa. Additionally, permeability hysteresis during stress relief was observed. These findings are relevant to deep geological construction activities where excavation leads to the development of an excavation damage zone and stress alterations, affecting overall fluid flow process.

地质介质中裂缝的渗透率演化在各种地质力学活动中发挥着关键作用，从能源回收到危险物质的深层地质处置。本文介绍了加拿大地盾结晶花岗岩在不同围压水平影响下裂缝渗透率演变的实验室和计算研究。进行稳态渗透率实验是为了评估由于大规模地下开挖而导致应力条件可能发生显着变化的区域裂缝渗透率的变化。使用高精度激光扫描仪捕获断裂表面的几何特征，从而能够对应力引起的流体力学行为进行数值模拟分析。系统地研究了各向同性应力和偏应力条件下的裂缝渗透率演化，包括四个加载-卸载序列和一系列顺序增加的偏应力。利用扫描获得的裂缝高程数据构建的模型，对围压增加下的裂缝闭合和相应的流体流动过程进行了模拟。结果表明，当三轴围压从 5 MPa 增加到 40 MPa 时，渗透率降低超过 50%。此外，还观察到应力消除期间的磁导率滞后。这些发现与深层地质施工活动相关，其中开挖导致开挖损伤区的发展和应力变化，影响整体流体流动过程。