Effect of particle shape and validity of GmaxGmax models for sand: A critical review and a new expression

Shear modulus of soils at small strains, GmaxGmax, is an important parameter in the design of geo-structures subjected to static and dynamic loading. Numerous models have been proposed in the literature for the prediction of GmaxGmax for saturated and dry sands. In this work, a novel approach is proposed, based on the concept of state parameter, for the examination of the validity of GmaxGmax equations in capturing the effects of void ratio and confining pressure on the small-strain behavior of granular soils. Four expressions of GmaxGmax from the literature are examined. It is shown that while the expressions examined may predict the measured values of GmaxGmax with some level of accuracy, dependencies to the state parameter are observed when the results are plotted against the state parameter. This is attributed to the exclusion of the effect of particle shape in the determination of the model parameters. To alleviate this deficiency, a new expression of GmaxGmax for dry and saturated sands is proposed and validated using a comprehensive set of resonant column test data performed at a range of initial void ratios, confining pressures, particle shapes and grain size distributions.