How Evolving Fabric Affects Shear Banding in Sand?

Gao, Z. and Zhao, J. (2014) How Evolving Fabric Affects Shear Banding in Sand? In: 10th International Workshop on Bifurcation and Degradation in Geomaterials, Hong Kong, China, 28-30 May 2014, pp. 21-26. ISBN 9783319135069

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Abstract

Fabric anisotropy affects importantly the overall behaviour of sand in-cluding its strength and deformation characteristics. While both experimental and numerical evidence indicates that soil fabric evolves steadily with the applied stress/strain, how evolving fabric influences the initiation and development of shear band in sand remains an intriguing question to be fully addressed. In this pa-per, we present a numerical study on strain localization in sand, highlighting the special role played by soil fabric and its evolution. In particular, a critical state sand plasticity model accounting for the effect of fabric and its evolution is used in the finite element analysis of plane strain compression tests. It is found that the in-itiation of shear band is controlled by the initial fabric, while the development of shear band is governed by two competing physical mechanisms, namely, the struc-tural constraint and the evolution of fabric. The evolution of fabric generally makes the sand response more coaxial with the applied load, while the structural constraint induced by the sample ends leads to more inhomogeneous deformation within the sand sample when the initial fabric is non-coaxial with the applied stress. In the case of smooth boundary condition, structural constraint dominates over the fabric evolution and leads to the formation of a single shear band. When the boundary condition is rough, the structural constraint may play a comparable role with fabric evolution, which leads to symmetric cross-shape shear bands. If the fabric is prohibited from evolving in the latter case, a cross-shape shear band pattern is found with the one initiated first by the structural constraint dominant over the second one. 1 Introduction

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Gao, Dr Zhiwei
Authors: Gao, Z., and Zhao, J.
Subjects:T Technology > TA Engineering (General). Civil engineering (General)
College/School:College of Science and Engineering > School of Engineering > Infrastructure and Environment
ISSN:1866-8755
ISBN:9783319135069
Copyright Holders:Copyright © 2014 Springer International Publishing
Publisher Policy:Reproduced with permission of Authors
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