Cement-based fracture grouting phenomenon of weathered granite soil

Abstract

The injection process of fracture grouting and/or fracture-permeation grouting is studied in this paper and analytical solutions are proposed to determine the fracture initiation pressure, the fracture length and thickness, and the pressure-induced filtration phenomenon for weathered granite soil, which is the most abundant soil type on the Korean peninsula. A theory is proposed and then verified through laboratory chamber tests. Experimental results show that fracture grouting occurs in unsaturated weathered granite soil, while fracture-permeation grouting occurs in saturated weathered granite soil. Also, through the experimental results with unsaturated weathered granite soil, it was found that the filtration phenomenon occurs when the water-cement ratio of the grout is less than 1.25. We were also able to demonstrate that the fracture initiation pressure as well as the fracture length and thickness obtained from the experiments match reasonably well with the theoretical values obtained from the analytical solutions.