The Relationship between Current Ground Stress and Permeability of Coal in Superimposed Zones of Multistage Tectonic Movement

Figure 3

(a) The relationship between volume density and GSI. (b) The relationship between natural gamma ray and GSI. (c) The relationship between borehole diameter of the X direction and GSI. (d) The relationship between borehole diameter of the Y direction and GSI.

(a)

(b)

(c)

(d)