Micromechanical behaviors and fabric within the immediate influence zone of granular-continuum interfaces

Abstract

Granular-continuum interfaces commonly exist in geotechnical engineering practices, such as foundations, reinforcements, and soil nailing. The mechanical behaviors and fabric of the interface are not only influenced by the soil properties but the interfaces, and normal stresses. Therefore, a thorough understanding of the granular-continuum interface is essential to engineering practices. This article investigates the interface shear behavior focusing on the normal stresses and soil densities by using the three-dimensional discrete element modeling (DEM). The influence zones resulting from counterface mobilization vary with the normal stresses and soil densities. The interface shearing problem physics obtained from DEM have been demonstrated to be consistent with the experiments. Based on the DEM model, the evolution of the micromechanical behaviors and fabric for the immediate influence zone of the interface at both failure and the critical state are investigated, such as fabric anisotropy, sliding fraction, and mechanical coordination number. The stress tensor and fabric tensor, determined from the granular assembly in the influence zone, are used to capture the interface shear strength. Results show that, due to the evolution of particle interlock and dilation, both the macro and micro mechanical parameters decrease mostly with the increasing confining stress at both failure and the critical state.

Keywords:

• Granular-continuum interface
• discrete element modeling
• fabric anisotropy
• micromechanics

Acknowledgements

This article was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that is use would not infringe privately owned rights. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This material is based upon work supported by the Department of Energy under Award Number DE-FG36-08GO18179.