Permeability block-scale stress

A BLOCK-SCALE STRESS-PERMEABILITY RELATIONSHIP OF A FRACTURED ROCK DETERMINED BY NUMERICAL EXPERIMENTS... 

Field observations indicate that the stress condition affects the flow characteristics of fractured rock mass (Barton et al., 1995 Ito and Hayashi, 2003 Pusch, 1989). Many laboratory investigations on single fractures also prove that the normal closure and shear dilation can significantly change the transmissivity of fractures (Makurat et al., 1990 Olsson et al., 2001). When it comes to the block scale stress-permeability relationship, the analytical models based on the orthogonal and/or persistent fracture model are available (Bai and Elsworth, 1994). However, analytical solutions do not generally exist for more realistic fracture systems. Furthermore, to the authors knowledge, block-scale study about the effect of shear dilations of fractures on the... 

For a given mean initial log(K) for the 1.56 m x 1.56 m blocks (Figure 4), we can simulate effective permeability ratios for the gridblock for different initial stresses and stress changes. Based on Equations 4 and 5, the local scale Rb is given by... 

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