Variation of Small-Strain Shear Modulus of Unsaturated Silt under Successive Cycles of Drying and Wetting

A new framework is developed to extend an existing small-strain shear modulus (Gmax) model to determine Gmax of unsaturated silty soils along different paths of the soil water retention curve (SWRC) including the scanning loops. The suitability of the proposed framework is validated against experimental results of a series of bender-element tests performed in this study and data reported in literature. Measured values of Gmax showed a slight hysteresis in the Gmax measurements along the scanning curves of the SWRC, with lower values along the wetting scanning paths. However, results indicated that the value of Gmax was recovered once the main drying path was reached. Results of this study also indicated that Gmax behavior of the silty specimen along the scanning curves was stress dependent. The model was observed to follow the experimental data along different paths of the SWRC including scanning curves.