- Title
- Investigating the elastoplasticity of an Australian soft rock based on laboratory test results
- Creator
- Karami, Mojtaba; Tolooiyan, Ali
- Date
- 2020
- Type
- Text; Journal article
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/173742
- Identifier
- vital:14723
- Identifier
-
https://doi.org/10.1016/j.enggeo.2020.105762
- Identifier
- ISBN:0013-7952 (ISSN)
- Abstract
- For the stability and deformation analysis of open-cut mines using numerical methods, one critical step is to identify and simulate the elastoplasticity of geomaterials comprising the open-cut batters. The Victorian Brown Coal (VBC) in Australia is a non-textbook geotechnical material with a hardening feature in compression leading to brittle failure while showing a sharp post-peak softening behaviour. In order to study different aspects of elastoplasticity including the hardening and post-peak softening behaviour of the VBC, a series of laboratory tests including one-dimensional oedometer and triaxial tests were carried out on undisturbed VBC specimens taken from 30 m to 50 m below the ground level in one of the largest VBC open-cut mines in Victoria. By post-processing of the triaxial and oedometer test results, a yielding phenomenon was identified at the boundary between the fully elastic and elastoplastic domains. The magnitude of the material stiffness in the elastic domain was found to be independent of the confining pressure in triaxial tests while governed by the chemical bonding of the coal particles. The post-yield behaviour, however, was a frictional hardening and ruled by the magnitude of the confining pressure leading to a failure envelope sensitive to the organic content of the material. In this paper, a unified failure envelope is defined for the VBC using the Hvorslev-type normalisation process. Furthermore, a nonlinear elastoplastic constitutive model was examined to describe the elastoplasticity of VBC in triaxial condition, which led to a good agreement between the experimental and numerical modelling results. © 2020 Elsevier B.V.; Financial support for this research has been provided by Earth Resources Regulation of the Victorian State Government Department of Economic Development, Jobs, Transport and Resources . The authors wish to acknowledge the support provided by the staff of the Yallourn Open Cut Brown Coal Mine, Energy Australia . The first author is funded by the Australian Government Research training program and Geotechnical and Hydrological Research Group (GHERG) scholarship programme at Federation University Australia . The authors are also grateful for the technical advice and assistance of Mr. Wayne Powrie (GHERG, Federation University Australia).
- Publisher
- Elsevier B.V.
- Relation
- Engineering Geology Vol. 276, no. (2020), p.
- Rights
- Copyright © 2020 Elsevier B.V.
- Rights
- This metadata is freely available under a CCO license
- Subject
- 4099 Other Engineering; 4019 Resources Engineering and Extractive Metallurgy; Elastoplasticity; Finite element; Hardening; Triaxial test; Victorian Brown Coal
- Reviewed
- Funder
- Financial support for this research has been provided by Earth Resources Regulation of the Victorian State Government Department of Economic Development, Jobs, Transport and Resources . The authors wish to acknowledge the support provided by the staff of the Yallourn Open Cut Brown Coal Mine, Energy Australia . The first author is funded by the Australian Government Research training program and Geotechnical and Hydrological Research Group (GHERG) scholarship programme at Federation University Australia . The authors are also grateful for the technical advice and assistance of Mr. Wayne Powrie (GHERG, Federation University Australia).
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