Numerical manifold simulation and medium-parameter analysis of the polymer grouting process in three-dimensional rock fractures

A three-dimensional (3D) numerical model for polymer grouting in rock mass fractures based on reaction kinetics theory is established in this article. The model integrates polymer reaction kinetics, compressible Newtonian fluid control, the energy balance accounting for foaming agent evaporation, and slurry density and viscosity models. A 3D rock fracture model simulates grouting in complex fractures and is validated by conventional viscosity simulations. In this study, the impact of fracture medium parameters on polymer diffusion is assessed, and slurry flow, pressure, viscosity, and density distributions during grouting are predicted. The research results indicated that (1) wider fractures reduce the overall slurry viscosity, rough fractures yield an uneven viscosity distribution, and smooth fractures (Joint Roughness Coefficient, JRC = 0) exhibit symmetrical viscosity. An increased fracture inclination boosts the slurry viscosity and reduces the reaction time. (2) Compared with viscosity, slurry density inversely trends with distance. (3) Larger fractures exhibit lower overall slurry diffusion pressures, which decrease with distance. Rough fractures experience higher pressure and fluctuations. A greater fracture inclination increases the overall diffusion pressure, with a monotonic increase at 60° and a parabolic distribution at 0°, peaking at the grouting port.