Role of morphologic indices on the variation of limiting void ratios for uniform sands

Abstract

New material parameters for sands, morphologic indices, are introduced to represent the relationship between particle size (D) and shape (R), and these indices are used to predict the limiting void ratios of sands from particular sites. In previous regression analyses, the authors determined a surface in the three-dimensional (3D) space made up of three variables: the limiting void ratio, D and R, where the two variables D and R are considered to be independent. In this study, however, it has been shown that D and R have a well-defined relationship for sand samples from the same site, where particles tend to have the same genesis and transport history. Due to the existence of a relationship between D and R, the function, which best fit the data in the 3D space, cannot be determined using the commonly used regression method. The orthogonal regression method is adopted to derive equations for the relationships among the three variables: limiting void ratio, D and R. The derived equations demonstrate the role of morphologic indices on the variation of limiting void ratios for uniform sands.