Experimental and Numerical Studies of Modified Polyurethane Diffusion Behavior in Vertical Cracks Based on Line Source Grouting

Abstract

The diffusion behavior of polyurethane slurry in vertical cracks, especially rough cracks, is not clear and needs to be studied to provide an effective reference for grouting design. In this study, the diffusion morphology and characteristics of modified polyurethane slurry in vertical cracks were investigated through modeling tests using the line source grouting method. Based on the viscous time-varying characteristics of the slurry, a numerical model of slurry diffusion was established using the joint FVM-VOF method. The numerical model was found to be accurate and reliable compared to the test results. Finally, building upon the basic theory of three-dimensional structure, a rough surface model with Gaussian distribution, more consistent with reality, was established. A numerical simulation system was then employed to study the diffusion morphology and characteristics of slurry in different rough cracks. The results indicate that the diffusion of modified polyurethane slurry within vertical cracks under line source grouting is roughly divided into three stages. Despite uniform crack opening, rougher roughness only increases the length of the crack, thereby reducing the straight-line distance of slurry diffusion. However, it has no significant effect on the flow and total distance of the slurry. Based on these findings, optimization of the grouting point arrangement is proposed.