Numerical study on microscopic behaviour of non-crushable cemented granular media subjected to direct shear test

ABSTRACT

Granular media, though discontinuous and heterogeneous, exhibit discrete behaviour at the grain scale and continuum behaviour at the macroscopic level. Understanding the correlation between micro-macro-mechanical parameters is crucial. The Discrete Element Method (DEM) effectively bridges this micro-macro-mechanical gap. This study simulates the Direct Shear Test (DST) using DEM software PFC2D on synthetic cemented granular media (CGM) under varying normal loads and strain rates. It examines micromechanical features and correlates them with macroscopic observations, focusing on confinement pressure and strain-rate dependency. Significant volumetric dilation is observed during shearing at low normal loads, which diminishes at higher normal loads. Particle-scale shear mobilization is explored through shear band formation in the sample. Grain-scale contact force distribution is highly heterogeneous throughout the sample. A probability distribution study is carried out to explore the bond breakage effect on the global response, which confirms the bond breakage to be a pressure and strain-dependent phenomenon.

KEYWORDS:

• Discrete element method
• PFC
• direct shear test
• granular assembly
• cemented granular media

Acknowledgments

The authors acknowledge the vital and constructive inputs from Dr Arghya Das, Associate Professor, Indian Institute of Technology, Kanpur, India. The authors would like to thank the anonymous reviewers, whose critical comments have elevated the standard of this work.

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Correction statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

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Funding

The author(s) reported there is no funding associated with the work featured in this article.