Fracture Mechanism in Overlying Strata during Longwall Mining

Figure 3

The contour maps of stress distribution of KS: (a) normal stress on the upper surface of KS; (b) normal stress on the upper surface of KS; (c) shear stress on the upper surface of KS; (d) normal stress on the section of KS; (e) normal stress on the section of KS.

(a)

(b)

(c)

(d)

(e)