Spherical Permeation Grouting Model of a Power-Law Fluid Considering the Soil Unloading Effect

Abstract

Previous studies have given little consideration to the influence of soil unloading effect on permeation grouting. A spherical permeation diffusion model considering the influence of soil unloading effect was established based on the theory of spherical permeation grouting to study the permeability and diffusion characteristics of a power-law fluid in unloaded soil. The permeation grouting model was compared and verified with the grout diffusion experiment conducted in the unloaded soil. A parametric analysis with the proposed model was performed. The result shows that the final diffusion radius of the grout increases with the increase of soil unloading degree, grouting pressure, water–cement ratio, and initial permeability coefficient but decreases with the increase of underground water pressure. The increment value of grouting pressure is equal to the increment value of underground water pressure under the same grouting time and grout diffusion radius. The influence of soil stress history, soil initial permeability coefficient, underground water pressure, and water–cement ratio should be comprehensively considered to determine the reinforcement range of permeation grouting. The proposed permeation grouting diffusion model is suitable for sandy soil with normal loading and unloading conditions, and the results analyzed by this model can provide some theoretical guidance for the tunnel vault grouting and bored pile postgrouting process.