Cyclic Behavior of Sand Stabilized by Colloidal Silica: Effects of Sample Preparation and Energy–Based Approach

Colloidal silica grouting is one of the most promising and innovative techniques for the mitigation of seismic liquefaction. It consists of injecting liquefiable soils with a harmless, low–viscosity, silica–based grout, forming a silica gel among soil particles after a certain time. This study discusses the effects of two techniques used for sample preparation on the cyclic response of stabilized sand by means of undrained cyclic triaxial test. Moreover, part of an existing test database by the same authors is analyzed within the framework of the dissipated energy concept. This energy–based approach provides an alternative way of describing the cyclic response of the stabilized sand. Experimental results show that: i) the cyclic strength of stabilized specimens prepared by moist tamping followed by grout injection is higher than that of stabilized specimens prepared by pluviation of dry sand into liquid grout; ii) the dissipated energy to liquefaction is greater for stabilized sand than for untreated sand; iii) characteristic patterns of dissipated energy are exhibited by stabilized sand samples, resembling the way they achieve the failure condition.