Effect of rock mass permeability and rock fracture leak-off coefficient on the pore water pressure distribution in a fractured slope
- Authors: Shaghaghi, Tahereh , Ghadrdan, Mohsen , Tolooiyan, Ali
- Date: 2020
- Type: Text , Journal article
- Relation: Simulation Modelling Practice and Theory Vol. 105, no. (2020), p. 1-13
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- Description: The reliable assessment of the stability of saturated slopes becomes a challenging task when slopes are consisting of discontinuous materials and containing pre-existing joints. The discontinuous nature of the slopes' material could increase the overall permeability of the slope, while existing joints facilitate groundwater leakage through the joint surfaces into the slope which subsequently exerts a major impact on deformation and the effective stress distribution. This paper aims to study the Pore Water Pressure (PWP) distribution changes in a saturated fractured slope by conducting advanced coupled pore fluid diffusion and stress-strain analyses, while investigating the sensitivity of results to the variation of permeability and leakage properties of fracture surfaces. Modelling of jointed slopes is carried out using the e-Xtended Finite Element Method (XFEM) in conjunction with the Finite Element Method (FEM). In this study, the fluid flow inside the joint is the major focus at which the constitutive response of the fluid inside the joint considers both tangential and normal flows. To demonstrate the state-of-the-art simulation technique presented in this paper, simulation of a fractured slope at the second largest open-pit mine in Australia is performed as a case study. This study shows the effect of a variable leak-off coefficient of the joint surfaces and the permeability magnitude on the pore water pressure distribution.
- Description: This research has been supported financially by the Earth Resources Regulation of the Victorian State Government Department of Economic Development, Jobs, Transport and Resources. The first and second authors are funded by the GHERG LV Batter Stability Project Scholarship and Faculty Tuition Scholarship of Federation University Australia.
Investigation of an Australian soft rock permeability variation
- Authors: Tolooiyan, Ali , Dyson, Ashley , Karami, Mojtaba , Shaghaghi, Tahereh , Ghadrdan, Mohsen
- Date: 2020
- Type: Text , Journal article
- Relation: Bulletin of Engineering Geology and the Environment Vol. 79, no. 6 (2020), p. 3087-3104
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- Description: In this study, permeabilities of Victorian Brown Coal (VBC) as an Australian soft rock are determined for a range of depths of a continuous coal seam located at the batter crest of the Yallourn brown coal open-cut mine in Victoria, Australia, by implementing a Lugeon packer testing procedure. Permeability values are determined both analytically and by numerical simulation and are compared with laboratory test results. Field testing resulted in permeabilities several orders of magnitude higher than laboratory testing, suggesting the existence of fractures common to lignite structures on a greater scale than can be observed in the laboratory. The variation of depth-based field and laboratory permeabilities is discussed, as well as the necessary conditions required for the numerical modelling of packer testing within VBC. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
- Description: Department of Economic Development, Jobs, Transport and Resources, DSDBI The second and third authors are funded by the Australian Government Research Training Program (RTP) and the GHERG scholarship programme.