PERMEATION GROUTING USING ALKALI-ACTIVATED GROUT FOR LIQUEFACTION CONTROL

Abstract

Earthquakes worldwide raise significant concerns, particularly in densely populated areas. In the field of geotechnical engineering, the persistent challenge of liquefaction demands attention. Soil liquefaction is an event where the surrounding soil loses its strength and behaves like a liquid when shear stress is experienced. Permeation grouting is a method of ground improvement that is compact and not destructive. It achieves densification and solidification of the ground by permeating grout solution at low pressure. Conventionally, solution-type grouts or cement-type grouts are used. However, the study proposes the use of alternative materials to help reduce the waste and carbon footprint of the grout. The mixture used in the study was a suspension-type grout composed of blast furnace slag and calcium carbonate powder, activated by sodium hydroxide. To quantify the feasibility of the grout formula for permeation grouting, several preliminary analyses and permeation tests were done. The results demonstrated that the grout mixture effectively developed sufficient strength for liquefaction control while maintaining low permeation pressure. Although clogging can occur with suspension-type grouts, adjusting variables such as injection rate and implementation of two-stage permeation mitigated negative effects. Optimization allowed the grout mixture to achieve a permeation radius of 0.8 meters during the one-dimensional test, slightly exceeding the ideal range of 0.75 meters. Subsequent two-dimensional and preliminary centrifuge modeling tests confirmed that filtration of grout particles in the soil occurred, and that alkali-activated grout could serve as a viable alternative for permeation grouting.