The Seismic Properties of a New Zealand Sand

The seismic site response analysis of sand deposits requires an understanding of the dynamic properties of the soils involved. Most of the dynamic soil data currently available in the literature has not been derived for New Zealand sands, and the relevance of this data to New Zealand pumice sands is rather unclear. An extensive experimental investigation of the dynamic response of a pumice sand was therefore undertaken, which investigated the liquefaction response from cyclic triaxial tests and the shear modulus response from bender element and dynamic torsion tests. The liquefaction results indicated that the liquefaction response was similar to that observed in quartz sands. The low strain shear modulus of the pumice sand was found to be significantly lower than that of quartz sands at similar relative densities, and the non linear constitutive relationship was markedly different from other sands, particularly in the mid strain range.