Experimental creep behaviour and modelling of silicified sand

Abstract

The stress–strain–time behaviour was investigated for sand that was treated by a new biologically inspired silicification process. This ground treatment method offers the potential to achieve similar performance as existing soil treatment methods using lower concentrations of environmentally benign component materials. This experimental study evaluated the influence of a polyelectrolyte pretreatment and test procedure on the fundamental strength of medium dense Ottawa 20/30 sand silicified with 20% sodium silicate. Samples were subjected to unconfined single-increment, unconfined incremental, and confined incremental creep tests. The results show that the creep behaviour of silicified samples is similar to the behaviour of traditionally treated sand. Fundamental strengths were approximately 50 kPa when unconfined, and ranged from 117 kPa to greater than 340 kPa when confined at 69 and 138 kPa, respectively. The data also show that incremental creep tests may be a more rapid means of determining parameters for creep modelling than the existing standardised single-increment test method. Parameters for modelling long-term deformation behaviour are consistent with published parameters for existing soil treatment methods even though compositional differences exist between the samples used in studies.