Residual State of Sands: Fid-Bau Portal

Residual State of Sands

Sadrekarimi, Abouzar / Olson, Scott M.

Abstract

The uniqueness and form of the critical state line for sands have been widely debated in the literature when particles crush. In this paper, the large-displacement behaviors of two clean sands and a silty sand are studied using ring shear and triaxial compression shear tests. Significant particle damage occurred in the shear bands of the ring shear tests. At very large shear displacements ( $> 10 m$ in the ring shear tests), particle damage and rearrangement/reorientation were complete in the ring shear tests, and a state of constant shear stress, constant effective stress, and constant volume was achieved in the crushed sand. Accordingly, a new definition is proposed for the residual state of damaged (crushed) sands, which is reached only within the shear band. It is shown that the critical state of the original sand (without particle crushing) and the residual state (with particle crushing) are independent of sand fabric (moist tamping and air pluviation) and consolidation stress ( $≈ 29 - 770 kpa$ ), and the same critical state is established in ring shear and triaxial compression shear tests. A unique residual state line is proposed for sands when particle damage occurs, which is significantly steeper than the critical state line.