ABSTRACT
The significant influence of parameters such as relative density and effective confining pressure in determining the amount of unit energy required for liquefaction was previously demonstrated. Similarly, it was found that the unit energy was nearly independent of the shear strain amplitude and the loading rate. Grain-size distribution has been traditionally identified as one of the most important factors affecting the liquefaction characteristics of sands. Torsional shear liquefaction testing of several soils with different grain-size characteristics made possible the development of a simple statistical relationship including relative density, effective confining pressure and well known grain-size distribution parameters such as uniformity coefficient and coefficient of curvature, to determine the amount of unit energy required for liquefaction. Inclusion of the latter two parameters considers the influence of particle size range as well as symmetry and shape of the gradation curve on the unit energy level required for liquefaction. Such statistical regression equation provides a measure of the resistance of a soil to liquefaction, in terms of energy per unit volume. This value can then be compared with the unit energy induced by a credible earthquake as determined by a suitable site response model to vertically propagating shear waves, to determine the liquefaction potential of a soil deposit.
