Understanding the hydro-mechanical (HM) coupling grouting process in fractured rock masses is vital for improving grouting effects. In this paper, a hybrid formulation of the unified-pipe network method coupled with zero-thickness interface elements is developed for simulating fracture grouting, named the unified pipe-interface element method (UP-IEM). The UP-IEM can naturally capture both the initiations and propagations of cracks without enrichments or crack tracking algorithms. Additionally, the grout flow in both the porous medium and fractures is solved in one solution system. A semi-explicit frame is built for solving the hydro-mechanical coupling problems, avoiding the potential numerical instability of implicit solutions and long computation time of explicit solutions. The proposed UP-IEM for simulating curved fracture paths in the near-hole region is validated by several numerical tests. Then, a parametric study is carried out to investigate the parameter effects on grout-driven fracture tortuosity and injection pressure. Finally, a grouting model with multiple rows of grouting holes is established according to actual grouting engineering and the simultaneous fracture grouting and sequential fracture grouting processes are analysed. The results show that the UP-IEM is potentially useful for optimizing the fracture grouting process.

了解裂隙岩体中的水力-机械 (HM) 耦合注浆过程对于提高注浆效果至关重要。在本文中，开发了一种结合零厚度界面单元的统一管网方法的混合公式，用于模拟裂缝灌浆，称为统一管界面单元方法（UP-IEM）。UP-IEM 可以自然地捕获裂纹的萌生和扩展，而无需富集或裂纹跟踪算法。此外，多孔介质和裂缝中的灌浆流动在一个溶液系统中求解。建立了一个半显式框架来解决水力耦合问题，避免了隐式解潜在的数值不稳定性和显式解计算时间长的问题。提议的用于模拟近孔区域弯曲裂缝路径的 UP-IEM 已通过多项数值试验得到验证。然后，进行参数研究以研究参数对注浆驱动裂缝曲率和注入压力的影响。最后根据实际注浆工程建立了多排注浆孔注浆模型，分析了同时裂缝注浆和顺序裂缝注浆过程。结果表明，UP-IEM 对优化裂缝注浆过程具有潜在的作用。根据实际注浆工程建立了多排注浆孔注浆模型，分析了同时裂缝注浆和顺序裂缝注浆过程。结果表明，UP-IEM 对优化裂缝注浆过程具有潜在的作用。根据实际注浆工程建立了多排注浆孔注浆模型，分析了同时裂缝注浆和顺序裂缝注浆过程。结果表明，UP-IEM 对优化裂缝注浆过程具有潜在的作用。