Numerical Simulation of Grout Diffusion in Rough Rock Fractures Considering Multiple Influencing Factors

The diffusion process and effect of grouting in rock fractures are affected by the grouting parameters, fracture parameters, and external environment. On the basis of theoretical research, a numerical simulation method of rough fracture grout propagation refinement based on Bingham–Papanastasiou rheological model is established in this paper. The propagation test of fracture grouting is designed, and the correctness of the numerical simulation method is verified by comparison between the model test and numerical simulation under standard working condition. Based on the standard working condition, the influences of grout water–cement ratio, grouting pressure, water-rich environment and filling rate on grout propagation are investigated, and the temporal and spatial distribution characteristics of velocity field and pressure field during grout propagation are analyzed. A simplified model of fissure-filling grouting infiltration is used to determine the geometric equivalence of the fissure-filling rate, and an empirical constant term fitting method for the Forchheimer infiltration equation of a Bingham flow-type grout is proposed.