Numerical Simulation of the Stress Field in Repeated Mining of Coal Seams Based on In Situ Stress Measurement

Figure 7

Distribution of principal stress on the main roof strike line. (a) Value of σ1 under the pillar. (b) Direction of σ1 under the pillar. (c) Value of σ1 under the gob. (d) Direction of σ1 under the gob.

(a)

(b)

(c)

(d)