Study on Spherical Diffusion Mechanism of Bingham Fluid Slurry Infiltration Grouting Considering Tortuous Effect of Porous Media

Abstract

Current studies on soil tortuosity models typically assume a single particle size, neglecting the impact of particle gradation and spatial arrangement on pore channels and structures. To address this limitation, we develop a tortuosity model that incorporates multiple factors by assuming ellipsoidal particles and accounting for their arrangement and gradation. This model, combined with the Bingham fluid flow equation in porous media, elucidates the spherical penetration grouting mechanism of Bingham fluids, considering both tortuosity and time‐varying viscosity. Using COMSOL Multiphysics, we simulate seepage to create a numerical program for Bingham fluid spherical seepage grouting that accounts for tortuosity and time‐varying viscosity. Theoretical analysis and simulations validate our proposed tortuosity model and diffusion mechanisms. Additionally, we examine the sensitivity of the diffusion radius to Bingham grout rheology, grouting pressure, groundwater pressure, and grouting pipe radius. The research results demonstrate that the established tortuosity theoretical model is in excellent agreement with numerical simulations, with a maximum error of less than 3%. The spherical permeation grouting diffusion mechanism of Bingham fluid, which accounts for the tortuosity effect of porous media, more closely matches the experimental test values, achieving an average error of 10.13% and a minimum error of 3%. Grouting pressure and groundwater pressure are key factors, and their interaction with the grouting pipe radius has the strongest effect. These research findings provide valuable theoretical support for designing construction controls related to restoration projects involving porous medium earth‐rock dams.