TY - EJOU AU - Liu, Xuewei AU - Sun, Jinze AU - Liu, Bin AU - Kang, Yongshui AU - Tian, Yongchao AU - Zhou, Yuan AU - Liu, Quansheng TI - Grouting Flow in Deep Fractured Rock: A State-of-the-Art Review of Theory and Practice T2 - Fluid Dynamics \& Materials Processing PY - 2025 VL - 21 IS - 8 SN - 1555-2578 AB - Grouting is a widely applied technique for reinforcing fractured zones in deep soft rock tunnels. By infiltrating rock fissures, slurry materials enhance structural integrity and improve the overall stability of the surrounding rock. The performance of grouting is primarily governed by the flow behavior and diffusion extent of the slurry. This review considers recent advances in the theory and methodology of slurry flow and diffusion in fractured rock. It examines commonly used grout materials, including cement-based, chemical, and composite formulations, each offering distinct advantages for specific geological conditions. The mechanisms of reinforcement vary significantly across materials, requiring tailored application strategies. The rheological properties of grouting slurries, particularly cement-based types, have been widely modeled using classical constitutive approaches. However, the influence of time- and space-dependent viscosity evolution on slurry behavior remains underexplored. Experimental studies have provided valuable insights into slurry diffusion, yet further research is needed to capture real-time behavior under multi-scale and multi-physics coupling conditions. Similarly, current numerical simulations are largely limited to two- and three-dimensional models of single-fracture flow. These models often neglect the complexity of fracture networks and geological heterogeneity, highlighting a need for more realistic and integrated simulation frameworks. Future research should focus on: (1) fine-scale modeling of slurry hydration and mechanical reinforcement processes; (2) cross-scale analysis of slurry flow under coupled thermal, hydraulic, and mechanical fields; and (3) development of real-time, three-dimensional dynamic simulation tools to capture the full grouting process. These efforts will strengthen the theoretical foundation and practical effectiveness of grouting in complex underground environments. KW - Grouting material; rheological characterization; diffusion behavior; numerical simulation method DO - 10.32604/fdmp.2025.068268