Abstract:Based on the field geological survey, measurement of spatial distribution of goaf, indoor rock mechanics tests, as well as engineering treatment of mechanical parameters, a three-dimensional numerical calculation model of mined-out area was established by using RHINO-FLAC3D coupling technology, and the stability of mined-out area was analyzed from the three aspects of displacement, maximum principal stress and plastic zone based on numerical simulation results. It shows that the mined-out area is currently in an unstable state, the ground collapse may occur again under the influence of external factors such as rainfall if effective measures are not taken. Based on the results of stability analysis and considering the economic benefits, construction difficulties and safety, the treatment plan was proposed, which used C15 concrete to fill from the exploration lines of 100~101and108~110 in the vertical direction to form 2 continuous vertical partition walls and the goaf of the midpiece of 270~290 and 378-to-surface to form horizontal partitions, then, using W7 bubble concrete to seal the two ends of the empty zone. The stability of the goaf achieved the expected results when treated by the program.