Fig. 15
From: Softening and instability evolution of strip coal pillar under water immersion in goaf
The dynamic evolutionary process of coal pillar softening and instability. (a) Local microscopic changes of coal pillar, (b) shear failure of coal pillar, (c) water softening of coal pillar-collapse, (d) pillar softening-creep, (e) overall instability of the coal pillar.
