Abstract
Roughness and tortuosity influence groundwater flow through a fracture. Steady flow through a single fracture can be described primitively by the well-known Cubic Law and Reynolds equation with the assumption that the fracture is made of smooth parallel plates. However, ignoring the roughness and tortuosity of the fracture will lead to inaccurate estimations of the flow rate. To obtain a more accurate flow rate through a rough fracture, this paper has derived a modified governing equation, taking into account the three-dimensional effect of the roughness. The equation modifies the Reynolds equation by adding correction coefficients to the terms of the flow rates, which are relative to the roughness angles in both the longitudinal and transverse directions. Experiments of steady seepage flow through sawtooth fractures were conducted. The accuracy of the modified equation has been verified by comparing the experimental data and the theoretical computational data. Furthermore, three-dimensional numerical models were established to simulate the steady flow in rough fractures with the triangular, sinusoidal surfaces and the typical joint roughness coefficient (JRC) profiles. The simulation results were compared with the calculation results of the modified equation and the current equations. The comparison indicates that the flow rate calculated by the modified equation is the closest to the numerical result.
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Abbreviations
- Q :
-
Volume flow rate
- W :
-
Apparent width of the fracture perpendicular to the flow direction
- D :
-
Apparent aperture of the fracture
- P :
-
Pressure
- Μ :
-
Fluid viscosity
- L :
-
Apparent length of the fracture in the flow direction
- x, y, z :
-
Global coordinates
- Ζ :
-
Local coordinate in the direction of the intersecting line between the local tiny segment and the x-z plane
- Η :
-
Local coordinate in the direction of the intersecting line between the local tiny segment and the y-z plane
- Ξ :
-
Local coordinate in the direction perpendicular to the local tiny segment ζ-η plane
- e ζ, e η , e ξ :
-
Unit vectors of the local coordinates (ζ, η, ξ)
- α x :
-
Inclination angle of the local tiny segment in the x direction < ζ, x >
- α y :
-
Inclination angle of the local tiny segment in the y direction < η, y >
- <α x >:
-
Effective rough angle in the x direction
- <α y >:
-
Effective rough angle in the y direction
- d(x, y):
-
Apparent aperture at point (x, y)
- <d>:
-
Average apparent aperture
- d z :
-
Apparent aperture of the fracture in the z direction
- d ξ :
-
True aperture of the local tiny segment in the ξ direction
- (i, j):
-
Numbers of the row and column of a tiny segment in the macroscopic fracture
- I, J :
-
Total numbers of the rows and columns of the tiny segments in the macroscopic fracture
- JRC:
-
Joint roughness coefficient
- K x :
-
K y permeability coefficients in the x, y directions
- l x :
-
Apparent length of the tiny segment projected in the x direction
- l y :
-
Apparent width of the tiny segment projected in the y direction
- l ζ :
-
True length of the tiny segment
- l η :
-
True width of the tiny segment
- τ x, τ y :
-
Tortuosity components in the x, y direction
- p ζi , p ηi :
-
Pressure of Section i in the segment of fracture in the ζ, η directions
- p xi , p yi :
-
Pressure of Section i in the segment of fracture in the x, y directions
- q ζ , q η :
-
Local flow rates per unit width in the segment of fracture in the ζ, η directions
- q x , q y :
-
Flow rates per unit width in the x, y directions
- Q ζ , Q η :
-
Local flow rates in the segment of fracture in the ζ, η directions
- Q xi , Q yi :
-
Flow rates of Section i rates in the x, y directions
- Q 0x , Q 0y :
-
Apparent flow rates calculated by the Cubic Law in the x, y directions
- Q x (i, j):
-
j) flow rate in the x direction of the No. i Row and No. j Column tiny segment
- Q A :
-
Flow rate in Fracture A
- Q B :
-
Flow rate in Fracture B
- Q C :
-
Flow rate in Fracture C
- Q s :
-
Flow rate from the numerical simulation
- Q CL :
-
Flow rate calculated from Cubic Law
- Q 2D, Q 3D :
-
Flow rate calculated from the 2D or 3D tortuosity corrected equation
- Q JRC :
-
Flow rate calculated from the 3D equation with JRC
- Z 2x , Z 2y :
-
Root-mean-square slope Z 2 in the x, y directions
- A :
-
Amplitude
- Λ :
-
Wavelength
- δ * :
-
Relative difference
- C :
-
Flow rate correction coefficient to modify Cubic Law
- C 2D, 3D :
-
Flow rate correction coefficient from the 2D, 3D equation to modify Cubic Law
- C JRC :
-
Flow rate correction coefficient from the 3D equation with JRC to modify Cubic Law
References
Bae DS, Kim KS, Koh YK, Kim JY (2011) Characterization of joint roughness in granite by applying the scan circle technique to images from a borehole televiewer. Rock Mech Rock Eng 44(4):497–504
Barton N, Choubey V (1977) The shear strength of rock joints in theory and practice. Rock Mech 10(1–2):1–54
Bear J (1972) Dynamics of fluids in porous media. Elsevier, New York, p 764
Belem T, Homand-Etienne F, Souley M (2000) Quantitative parameters for rock joint surface roughness. Rock Mech Rock Eng 33(4):217–242
Brown SR (1987) Fluid flow through rock joints: the effect of surface roughness. J Geophys Res Solid Earth 92(B2):1337–1347, 1978–2012
Chen SH, Feng XM, Isam S (2008) Numerical estimation of REV and permeability tensor for fractured rock masses by composite element method. Int J Numer Anal Methods 32(12):1459–1477
Collins RE (1961) Flow of fluids through porous materials. Reinhold, New York
Crandall D, Ahmadi G, Smith DH (2010a) Computational modeling of fluid flow through a fracture in permeable rock. Transp Porous Media 84(2):493–510
Crandall D, Bromhal G, Karpyn ZT (2010b) Numerical simulations examining the relationship between wall-roughness and fluid flow in rock fractures. Int J Rock Mech Min 47(5):784–796
Drazer G, Koplik J (2000) Permeability of self-affine rough fractures. Phys Rev E 62(6):8076
Elsworth D, Goodman RE (1986) Characterization of rock fissure hydraulic conductivity using idealized wall roughness profiles. Int J Rock Mech Min Geomech Abstr Pergamon 23(3):233–243
Fluent INC (2006) FLUENT 6.3 user’s guide. Fluent documentation
Gao Y, Louis NYW (2013) A modified correlation between roughness parameter Z2 and the JRC. Rock Mech Rock Eng, available online: Doi 10.1007/s00603-013-0505-5
Ge S (1997) A governing equation for fluid flow in rough fractures. Water Resour Res 33(1):53–61
Geng K (1994) Research and application of the mechanic–percolating interaction of complex rockhead. PhD thesis, Tsinghua University, Beijing (in Chinese)
Grasselli G, Egger P (2003) Constitutive law for the shear strength of rock joints based on three-dimensional surface parameters. Int J Rock Mech Min 40(1):25–40
Grasselli G, Wirth J, Egger P (2002) Quantitative three-dimensional description of a rough surface and parameter evolution with shearing. Int J Rock Mech Min 39(6):789–800
Jiang Y, Li B, Tanabashi Y (2006) Estimating the relation between surface roughness and mechanical properties of rock joints. Int J Rock Mech Min 43(6):837–846
Koyama T, Neretnieks I, Jing L (2008) A numerical study on differences in using Navier-Stokes and Reynolds equations for modeling the fluid flow and particle transport in single rock fractures with shear. Int J Rock Mech Min 45(7):1082–1101
Lomize GM (1951) Flow in fractured rocks. Gosenergoizdat, Moscow, p 127
Louis CA (1969) Study of groundwater flow in jointed rock and its influence on the stability of rock masses. Imperial College of Science and Technology, London
Mah J, Samson C, McKinnon SD, Thibodeau D (2013) 3D laser imaging for surface roughness analysis. Int J Rock Mech Min 58:111–117
Moharrami A, Hassanzadeh Y, Salmasi F, Moradi G, Moharrami G (2013) Performance of the horizontal drains in upstream shell of earth dams on the upstream slope stability during rapid drawdown conditions. Arab J Geosci 7:1957–1964, 1–8
Mourzenko VV, Thovert JF, Adler PM (1995) Permeability of a single fracture; validity of the Reynolds equation. J Phys II France 5(3):465–482
Myers NO (1962) Characterization of surface roughness. Wear 5(3):182–189
Nazridoust K, Ahmadi G, Smith DH (2006) A new friction factor correlation for laminar, single-phase flows through rock fractures. J Hydrol 329(1):315–328
Neuzil CE, Tracy JV (1981) Flow through fractures. Water Resour Res 17(1):191–199
Petchsingto T, Karpyn ZT (2009) Deterministic modeling of fluid flow through a CT-scanned fracture using computational fluid dynamics. Energy Sources, Part A 31(11):897–905
Rasouli V, Hosseinian A (2011) Correlations developed for estimation of hydraulic parameters of rough fractures through the simulation of JRC flow channels. Rock Mech Rock Eng 44(4):447–461
Rutqvist J, Wu Y-S, Tsang C-F, Bodvarsson G (2002) A modeling approach for analysis of coupled multiphase fluid flow, heat transfer, and deformation in fractured porous rock. Int J Rock Mech Min 39:429–442
Sanei M, Faramarzi L, Goli S, Fahimifar A, Rahmati A, Mehinrad A (2013) Development of a new equation for joint roughness coefficient (JRC) with fractal dimension: a case study of Bakhtiary Dam site in Iran. Arab J Geosci 1–11
Scesi L, Gattinoni P (2007) Roughness control on hydraulic conductivity in fractured rocks. Hydrogeol J 15(2):201–211
Snow DT (1969) Anisotropic permeability of fractured media. Water Resour Res 5(6):1273–1289
Streltsova TD (1976) Hydrodynamics of groundwater flow in a fractured formation. Water Resour Res 12(3):405–414
Tatone BS, Grasselli G (2010) A new 2D discontinuity roughness parameter and its correlation with JRC. Int J Rock Mech Min 47(8):1391–1400
Tatone BS, Grasselli G (2013) An investigation of discontinuity roughness scale dependency using high-resolution surface measurements. Rock Mech Rock Eng 46(4):657–681
Tsang YW (1984) The effect of tortuosity on fluid flow through a single fracture. Water Resour Res 20(9):1209–1215
Tse R, Cruden DM (1979) Estimating joint roughness coefficients. Int J Rock Mech Min Geomech Abstr Pergamon 16(5):303–307
Waite ME, Ge S, Spetzler H (1999) A new conceptual model for fluid flow in discrete fractures: an experimental and numerical study. J Geophys Res Solid Earth 104(B6):13049–13059, 1978–2012
Walsh JB, Brace WF (1985) The effect of pressure on porosity and the transport properties of rock. J Geophys Res Solid Earth 89(B11):9425–9431, 1978–2012
Walsh R, McDermott C, Kolditz O (2008) Numerical modeling of stress-permeability coupling in rough fractures. Hydrogeol J 16(4):613–627
Xiao W, Xia C, Wei W, Bian Y (2013) Combined effect of tortuosity and surface roughness on estimation of flow rate through a single rough joint. J Geophys Eng 10(4):045015
Xiong X, Li B, Jiang Y, Koyama T, Zhang C (2011) Experimental and numerical study of the geometrical and hydraulic characteristics of a single rock fracture during shear. Int J Rock Mech Min 48(8):1292–1302
Zhang Z, Nemcik J (2013) Friction factor of water flow through rough rock fractures. Rock Mech Rock Eng 46(5):1125–1134
Zhang Z, Nemcik J, Ma S (2013) Micro- and macro-behaviour of fluid flow through rock fractures: an experimental study. Hydrogeol J 21(8):1717–1729
Zimmerman RW, Kumar S, Bodvarsson GS (1991) Lubrication theory analysis of the permeability of rough-walled fractures. Int J Rock Mech Min Geomech Abstr Pergamon 28(4):325–331
Zimmerman RW, Chen DW, Cook NGW (1992) The effect of contact area on the permeability of fractures. Hydrogeol J 139(1):79–96
Zimmerman RW, Al-Yaarubi A, Pain CC, Grattoni CA (2004) Non-linear regimes of fluid flow in rock fractures. Int J Rock Mech Min 41:163–169
Acknowledgments
This work was financially supported by the National Natural Science Foundation of China (Grant No. U1361103, 51479094, and 51009079) and National Basic Research Program of China (Grant No. 2011CB013500).
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He, G., Wang, E. & Liu, X. Modified governing equation and numerical simulation of seepage flow in a single fracture with three-dimensional roughness. Arab J Geosci 9, 81 (2016). https://doi.org/10.1007/s12517-015-2036-8
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DOI: https://doi.org/10.1007/s12517-015-2036-8