Instability of Gypsum Mining Goaf Under the Influence of Typical Faults

Abstract

Mine collapse is a common geological hazard associated with mining areas. In this paper, the goaf of a gypsum mine under the influence of typical faults is chosen as an example, and the stress on the center of the goaf roof is examined through theoretical analysis. The safety factors of the pillar at -127 m, -140 m, and -160 m are evaluated to be 1.471, 1.469, and 1.467, respectively, based on the Wilson theory. It is concluded that the structural parameters of the mining stope are reasonable without considering the influence of the fault. Furthermore, the numerical simulation by FLAC3D is used to verify the analytical results and to study the influence of typical faults on the stress and displacement of the goaf. The results showed that the load of the roof and the pillars at a distance from the fault was larger than the load near the fault. First, the roof at this location is pulled. Next, cracks appear and develop. Then, the middle of the stope roof is pulled and falls, and the overburden strata move. Finally, the unstable strata are transmitted to the surface, and the ground surface of the mining area subsides.

Keywords

• Gypsum mine
• typical fault
• instability of goaf
• finite difference method