Fig. 12

Stress distribution of floor under the graben structure condition. Compared with that under normal mining conditions, in the horizontal direction, the horizontal stress increases by approximately 20%, the tensile stress area of the goaf decreases, and the pressure ball caused by the floor pressure presents a symmetrical distribution. The shear stress on the side of the small-dip fault increases under the graben structure, whereas the shear stress on the side of the large-dip fault decreases.