Strain-dependent Fluid Flow Defined Through Rock Mass Classification Schemes

Summary¶Strain-dependent hydraulic conductivities are uniquely defined by an environmental factor, representing applied normal and shear strains, combined with intrinsic material parameters representing mass and component deformation moduli, initial conductivities, and mass structure. The components representing mass moduli and structure are defined in terms of RQD (rock quality designation) and RMR (rock mass rating) to represent the response of a whole spectrum of rock masses, varying from highly fractured (crushed) rock to intact rock. These two empirical parameters determine the hydraulic response of a fractured medium to the induced-deformations. The constitutive relations are verified against available published data and applied to study one-dimensional, strain-dependent fluid flow. Analytical results indicate that both normal and shear strains exert a significant influence on the processes of fluid flow and that the magnitude of this influence is regulated by the values of RQD and RMR.

[1]  P. Witherspoon,et al.  Stress-Fluid Flow Analysis of Fractured Rocks , 1983 .

[2]  W. F. Bawden,et al.  INFLUENCE OF FRACTURE DEFORMATION ON SECONDARY PERMEABILITY-A NUMERICAL APPROACH , 1980 .

[3]  Stephen R. Brown,et al.  Fluid flow through rock joints: The effect of surface roughness , 1987 .

[4]  A. Gangi,et al.  Variation of whole and fractured porous rock permeability with confining pressure , 1978 .

[5]  Z. Bieniawski,et al.  A nonlinear deformation modulus based on rock mass classification , 1990 .

[6]  E. Hooper.  FLUID MIGRATION ALONG GROWTH FAULTS IN COMPACTING SEDIMENTS , 1991 .

[7]  Derek Elsworth,et al.  Three-dimensional effects of hydraulic conductivity enhancement and desaturation around mined panels , 1997 .

[8]  F. Skoczylas,et al.  A study of the intrinsic permeability of granite to gas , 1995 .

[9]  N. Barton,et al.  Strength, deformation and conductivity coupling of rock joints , 1985 .

[10]  Terry Engelder,et al.  The permeability of whole and jointed Barre Granite , 1979 .

[11]  M. S. King,et al.  Experimental ultrasonic velocities and permeability for sandstones with aligned cracks , 1995 .

[12]  O. Richmond,et al.  Interaction of compaction near mine openings and drainage of pore fluids from coal seams , 1984 .

[13]  Z. Şen.  Theoretical RQD-porosity-conductivity-aperture charts , 1996 .

[14]  D. Elsworth,et al.  Evaluation of the post-mining groundwater regime following longwall mining , 1997 .

[15]  Derek Elsworth,et al.  Evaluation of groundwater flow into mined panels , 1993 .

[16]  Zhou Gang,et al.  Permeability-strain equations corresponding to the complete stress—strain path of Yinzhuang Sandstone , 1994 .

[17]  F. Descoeudres,et al.  Permeability predictions for jointed rock masses , 1995 .

[18]  Ronald A. Nelson,et al.  Experimental Study of Fracture Permeability in Porous Rock , 1977 .

[19]  Edward J. Cording,et al.  Hydromechanical behavior of rock joints: A re-interpretation of published experiments , 1995 .

[20]  J. Franklin,et al.  Prediction of water flow into rock tunnels: an analytical solution assuming an hydraulic conductivity gradient , 1993 .

[21]  Nick Barton,et al.  Joint conductivity variation due to normal and shear deformation , 1991 .

[22]  R. Pusch,et al.  Alteration of the hydraulic conductivity of rock by tunnel excavation , 1989 .

[23]  H. C. Heard,et al.  Effect of pressure and stress on water transport in intact and fractured gabbro and granite , 1980 .

[24]  Lawrence W. Teufel,et al.  Permeability changes during shear deformation of fractured rock , 1987 .