The Utilisation of Colloidal Silica Grout in Soil Stabilisation and Liquefaction Mitigation: A State of the Art Review

Abstract

Liquefaction mitigation in already existing sites has become a cause of concern for geotechnical engineers across the world. One of the possible solutions for such sites is the recently developed technique called colloidal silica grouting. The technique utilises the slow injection of colloidal silica grout at the edge of the location through injection wells and delivers it to the required location through natural groundwater flow. Later, silica particles gel and bind the soil particle together by changing the pH that, in turn, increases the strength and rigidity of loose soil. The test results obtained from the laboratory and field studies are promising and feasible to recommend colloidal silica as a potential grout material for various soil engineering applications. The present review explains the use of colloidal silica stabilisation for ground enhancement and discusses the treatment method, together with the gelation and significant factors affecting the gel formation. The current paper reviews the tests performed in colloidal silica treated soil to determine the mechanical properties, hydraulic conductivity, and evaluation of liquefaction potential. Scanning electron microscopy analysis of colloidal silica treated soil was also included to explore the microstructural bonding of soil grouted with colloidal silica. Also, the advantages and challenges of colloidal silica grouting techniques in ground improvement are included in the study. Furthermore, future research scope of colloidal silica treated soil in unexplored areas is also mentioned based on the current literature review.