Experimental Study on the Law of the Ground Surface Movement on the Old Goaf in Different Mining Conditions

The formation process of goaf was dynamically simulated by similar material simulation esperiment. After mining coal was finished and the goaf was basically stable, deformation regularity of surface migrating was studied under gradual loading in different lacation of goaf . The results show: the residual deformation caused by load arranged on both sides of goaf is bigger than that caused by load arranged in the central of goaf. And the maximum values of residual deformation occur on both sides of goaf. The different mining conditions, load location and size will affect the residual deformation. In single mining conditions, a larger load in the both sides of goaf ,the greater the residual deformation.