Influence of Coupling Effects between Gravel Soil Porosity and Cement Grout Weight on Diffusion Laws and Morphologies of Penetration Grouting

The practice and theory of grouting engineering show that both injected medium porosity and grouting fluid weight play an important influence on the diffusion law and morphology of penetration grouting. However, the effects have not been well studied in the context of existing penetration grouting mechanisms. In this paper, the actual diffusion law and morphology of cement grout into the gravel soil are studied on the basis of indoor experiments, mathematical statistics, and theoretical analyses. Then, the three-dimensional space diffusion trajectory equation was quantitatively characterized. The influence of the coupling effect between gravel soil porosity and cement grout weight on diffusion morphologies of penetration grouting was discussed by the definition of the morphological deviation rate. Results show that actual penetration diffusion dimensions of cement grout into the gravel soil differ from that of theoretical values calculated by the penetration grouting mechanism, and its spatial diffusion morphology is approximated as ellipsoid. The coupling effect between gravel soil porosity and cement grout weight have a relatively significant effect on the diffusion morphologies of penetration grouting except for gravel soil with porosity <0.5 infiltrated by Newton-type and <0.4 by power-law-type cement grout, respectively. This influence is particularly significant when Bingham-type cement grout was penetrated into gravel soil with a porosity of >0.5. The research results can provide theoretical support and technical references for the practical grouting engineering of gravel soil.