Investigate the influence of the in-situ stress conditions on the grout penetration process in fractured rocks using the combined finite-discrete element method
Grouting is widely used to reduce hydraulic conductivity and enhance the strength of rock masses in geotechnical engineering. With the depletion of shallow resources and expansion of human activities, more underground projects are operated in deeper underground under high in-situ stress conditions. Understanding and controlling the grout penetration process under high in-situ stress conditions are critical to optimizing the grouting process in deep underground projects. In this work, we develop a FDEM-grouting model to study the effect of in-situ stress conditions on the grout penetration process by combining the combined finite-discrete element method (FDEM) with a grout simulator. The ability of FDEM-grouting to model grout penetration in fracture networks is confirmed by numerical tests compared with analytical solutions. The necessity of considering the effects of the fracture roughness, in-situ stress and HM coupling on the grout penetration process are discussed. A persistent fracture network is designed to investigate the grout penetration process under various in-situ stress conditions. The results show that the in-situ stress conditions can greatly affect the grout penetration in fracture networks. The anisotropic grout penetration under in-situ stress conditions is potentially useful for improving the grouting design.
Keywords: Combined finite-discrete element method (FDEM), Grout penetration, In-situ stress condition, Hydro-mechanical coupling problem,