Simple Scale Effect Model for the Volumetric Behavior of Rockfill Materials

Abstract

Bridging the mechanical response of rockfill materials with laboratory grading curves and field grading curves is of obvious importance in rockfill dam engineering and has been a great challenge for geotechnical researchers for decades. In this study, a novel approach was proposed to consider the scale effect on the volumetric behavior of rockfill materials. The proposed scale effect model was incorporated into an existing volume–stress equation and was validated by both the experimental data in the literature and the one-dimensional compression test results performed by the authors. Furthermore, it was demonstrated that the single scale-related parameter in the model, namely, the Weibull modulus m, obtained experimentally from the particulate scale, can also be applied for granular assemblies. This work provides not only a theoretical framework to understand the scale effect on the volumetric behavior of rockfill materials but also a very promising application in rockfill dam engineering: one can effectively estimate the volumetric behavior of a rockfill material with the field grading curve using simply experimentally obtained volume–stress data of a downscaled material and the single-particle crushing tests data of the composing rockfill particles.