Study on Mechanical Model for Postpeak Shear Behavior of Rock Joints Based on Degradation Characteristics of the 3D Morphology

Table 3

Box-counting dimension for upper and lower surfaces.

u (mm)	Upper surfaces		Lower surfaces
	Expression	R^2	Expression	R^2
0	lgN = −1.871 lgS + 5.451	0.996	lgN = −1.836 lgS + 5.410	0.992
2.5	lgN = −1.820 lgS + 5.342	0.993	lgN = −1.811 lgS + 5.354	0.991
5.0	lgN = −1.800 lgS + 5.299	0.992	lgN = −1.758 lgS + 4.953	0.979
7.5	lgN = −1.749 lgS + 5.190	0.989	lgN = −1.738 lgS + 5.196	0.986
10.0	lgN = −1.676 lgS + 5.023	0.985	lgN = −1.694 lgS + 5.100	0.982
12.5	lgN = −1.621 lgS + 4.899	0.981	lgN = −1.663 lgS + 5.023	0.983