Abstract:

The influence of the excavation above goaf on the displacement of rock cover is analyzed by means of numerical simulation method, with the excavation of a large underground space through the goaf of No. 8 coal seam of Nankeng Mine in Shanxi province as an example. The study shows that the control layer and its stability play an important role in maintaining the stability of the underground space during excavation. The control layer moves in the longitudinal direction under the action of stress, and it stops moving some time after the excavation face passes the goaf. Discrete layer is formed due to the continuous movement of the noncontrol layers. The deformation of the rock cover on both wings above the goaf moves towards the center. The stability of the control layer plays a very important role in the deformation of the rock cover. The paper can provide theoretical basis for the further study on the rock layer control technology in the excavation of underground space above goafs.

Key words: underground space, excavation, goaf, rock cover, deformation, numerical simulation