Yes, and for a good reason! Cel-Fi is controlled by and operates as an extension of an operator's network. The friction angles in Table 14-1 should be used only as guidelines because actual values vary C ). Shear Stress angles for a variety of rock types (Barton 1973 Jaeger and Cook 1976). FIGURE 14-6 Effect of surface roughness and normal stress on friction angle of fracture surface (Wyllie 1992).
