ABSTRACT
Improving excavation front stability of tunnels is very important. This application falls under the term “soil improvement.” Soil improvement techniques are different methods of improving the strength, stiffness, and other technical properties of soils. Mechanical, hydraulic, physical/chemical, and composite modifications are the broad categories into which soil improvement can be divided. As far as physical/chemical changes are concerned, chemical grouting is a soil improvement technique in which chemical injection mortars are injected into the soil to improve its properties. Technology in the grouting industry is constantly evolving. Low-carbon binders such as colloidal silica, acrylates, and polyurethanes are increasingly used to improve the mechanical properties of soils. This paper presents a summary of interpretations of past grouting tests performed by injecting colloidal silica, acrylates, and polyurethanes into sands. Statistical and mathematical interpretation of the data was provided to assess the robustness of the data.
