Silicate-Stabilized Sands

Strengthening and stiffening of a chohesionless, sandy soil in-situ by means of injection of a silicate solution that gels with time, is a technique that is finding growing applicability to geotechnical problems. This paper presents the results of a comprehensive series of tests designed to provide an engineering data base to describe the behavior of silicate-stabilized sands. Basically, it is found that the injection of the grout solution into the sand adds a cohesion component to its strength without significantly altering its frictional component of strength. Key variables that influence the behavior of the silicate are the grout mix components, confining pressure, loading rate, curing environment, curing time, and grain size of the soil. Loading rate is important because the grouted soil tends to creep with time and can fail in creep rupture. Only 50% of the strength defined in a rapid load test can be relied upon for long-term load conditions.