Numerical investigation of the flow characteristics and permeability of 2D irregular columnar jointed rock masses
ISSN: 0264-4401
Article publication date: 19 May 2021
Issue publication date: 7 December 2021
Abstract
Purpose
The objective of this paper is to provide a better understanding of the effect of irregular columnar jointed structure on the permeability and flow characteristics of rock masses.
Design/methodology/approach
An efficient numerical procedure is proposed to investigate the permeability and fluid flow in columnar jointed rock masses (CJRMs), of which the columnar jointed networks are generated by a modified constrained centroid Voronoi algorithm according to the field statistical results. The fractures are represented explicitly by using the lower-dimensional zero thickness elements. And the modeling scheme is validated by a benchmark test for flow in fractured porous media. The effective permeability and representative elementary volume (REV) size of CJRMs are estimated using finite element method (FEM). The influences of joint density and variation coefficient of columnar joint structure on the permeability of the rock mass are discussed.
Findings
The simulation results indicate that the permeability is scale-dependent and tends to be stable with increase of model size. The hydraulic REV size is determined as 3.5 m for CJRMs in the present study. Moreover, the joint density is a dominant factor affecting the permeability of CJRMs. The average permeability of columnar jointed structures increases linearly with the joint density under the same REV size, while the influence from the coefficient of variation can be neglected.
Originality/value
The present paper investigates the REV size of the CJRMs and the effect of joint parameters on the permeability. The proposed method and the results obtained are useful on understanding the hydraulic characteristic of the irregular CJRMs in engineering projects.
Keywords
Acknowledgements
The work presented in this paper is supported by the National Key R&D Program of China (No. 2018YFC0407004), Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. KYCX19_0421, 2019B73414), Fundamental Research Funds for the Central Universities (Grant No. B200202083) and the National Natural Science Foundation project of China (No. 11772116) and the Qinglan project.
Citation
Cheng, Z., Wang, H., Xu, W. and Yan, L. (2021), "Numerical investigation of the flow characteristics and permeability of 2D irregular columnar jointed rock masses", Engineering Computations, Vol. 38 No. 10, pp. 4091-4110. https://doi.org/10.1108/EC-10-2020-0603
Publisher
:Emerald Publishing Limited
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