Solid waste slurry grouting transformation mechanism of loose sand layer based on slurry-water replacement effect
Physics of Fluids, 36(7):073330, 2024.
Summary
Water-bearing sand layers can become pathways for dangerous water and sand inflows during coal extraction. This study examines how grout moves through such layers when injected slurry displaces groundwater, while accounting for the tortuous paths within the pore network. A spherical diffusion relationship is developed for a power-law grout, and its predictions are assessed with a purpose-built laboratory arrangement. Three-dimensional COMSOL simulations then examine how sand porosity, the separation between injection and drainage holes, injection pressure, and slurry viscosity change the treated volume. Among these variables, injection pressure has the strongest influence, followed by hole spacing, sand porosity, and viscosity. The combined experimental and numerical results suggest that deliberate slurry-water displacement can increase the reach of grouting and improve treatment of loose, saturated sand under high water pressure. The approach provides a basis for designing grouting layouts and operating conditions in mining applications.