Fig. 12

Vertical stress distribution in goaf of 13,311 working face. After verifying the reasonableness of the stress environment of the working face’s hollow zone, running to equilibrium after assigning the Double-yield model to the rock layer of the working face 13311 and the collapsed zone above, and arranging the measuring line along the working face, the vertical stress recovered to 9.7MPa at 70m from the edge of the hollow zone, close to the original rock stress.