The stability of rock engineering is generally dominated by existing seepage, particularly the seepage evolution due to the rock masses damage. However, the current research generally overlooks the seepage-damage coupling when studying the hydraulic-mechanical coupling effect in rock masses. This study aims to propose a dual-medium model, including equivalent continuous and discrete fracture media to study the coupled seepage-damage effect in fractured rock masses. The dual-medium seepage model considers the substantial water storage of the fracture network and the high conductivity of major large-scale fractures. Also, the seepage evolution is constructed to be a function of stress, seepage pressure and length of crack propagation in the rock mass. To illustrate the new model's application, a case of high-pressure water injection in a coal seam has been investigated to reveal the damage evolution in the coal seam. The results indicate that during the initial stage of the water injection, the seepage pressure in the discrete fracture medium increases faster than that in the equivalent continuous medium. Moreover, the seepage pressure difference between the two media gradually decreases with the increase of the seepage time, eventually forming a stable seepage field in the coal seam. Notably, the high-pressure water injection in the coal seam significantly affects the distribution of the coal seam's stress field, resulting in the effective minimum principle stress changing from compression to tension states. Also, during coal seam water injection, the damage zone and major fracture apertures in the coal seam gradually increase with increasing injection time.

岩石工程的稳定性一般以存在的渗流为主，尤其是岩体破坏引起的渗流演化。然而，目前的研究在研究岩体水力-机械耦合效应时，普遍忽略了渗流-损伤耦合。本研究旨在提出一个包括等效连续和离散裂缝介质的双介质模型，以研究裂隙岩体中的耦合渗流-损伤效应。双重介质渗流模型考虑了裂缝网络的大量储水量和主要大型裂缝的高电导率。此外，渗流演化被构造为应力、渗流压力和裂纹扩展长度的函数在岩体中。以煤层高压注水为例说明新模型的应用已被调查以揭示煤层中的损伤演变。结果表明，在注水初始阶段，离散裂缝介质中的渗流压力比等效连续介质中的渗流压力增加得更快。而且随着渗流时间的增加，两种介质的渗流压差逐渐减小，最终在煤层中形成稳定的渗流场。值得注意的是，煤层高压注水显着影响了煤层应力场的分布，导致有效最小主应力由压缩状态变为拉伸状态。同时，在煤层注水过程中，随着注水时间的增加，煤层的损伤带和主要裂缝孔径逐渐增大。