Hydromechanical characterization of soil-rockfill mixtures

Abstract

In order to improve the rather insufficient knowledge about the hydromechanical behavior of soil–rockfill mixtures (SRMs) applied in embankment dams, a testing program was undertaken in which several mixtures with different coarse fractions (CFs) were tested (30, 40, 50, and 70%). SRMs are an environmentally-friendly material that takes advantage of the material excavated for spillways, cut-off trenches, outlet works, and other structures that can be reused. This study presents, for the first time, a systematic experimental program for this type of natural material, involving isotropic and K0 compression tests, undrained triaxial tests, and permeability tests for different CFs. It aims to improve the knowledge about the behavior of this material. All tests performed revealed that SRMs present the same mechanical behavior irrespective of the CF of the mixture. Also, it may be concluded that it is beneficial to add soil to rockfill to constitute an SRM because this results in a stiffer material.