Abstract
<jats:p>Research studies using centrifuge modelling is a prime choice for investigation of soil-structure interaction in earthquake geotechnical engineering. Centrifuge studies are most effective when supported by complementary numerical modelling aimed at conducting expanded parametric studies. The numerical studies use soil constitutive models which need to be calibrated against soil element tests representing the dominant stress paths, stress and strain levels induced in centrifuge models. Currently, there is a gap in the available laboratory data with no database on the small-strain shear stiffness of soil subjected to anisotropic consolidation, thus accurate calibration of soil constitutive models for vertically propagating shear waves in centrifuge is not possible. This work presents results from soil laboratory tests to address this gap and provide a new dataset on the small-strain shear stiffness of soil subjected to anisotropic consolidation compared with tests under an isotropic stress state. To this aim, resonant column tests, supported by small-strain torsional shear tests, were conducted on triaxial samples under a range of different stress and strain levels representative of those observed in centrifuge tests on shear wave propagation. The results show that the initial small-strain stiffness is primarily governed by the vertical stress component. The difference in the shear stiffness degradation G/G0 between corresponding anisotropically and isotropically consolidated samples increases with increasing shear strain. Recommendations for using simple analytical expressions for evaluating the small-strain stiffness characteristics of soil under anisotropic consolidation are provided.</jats:p>