Abstract: The maximum damage depth and its evolution regularity of the rock mass of Longmeng coal mine seam floor are numerical simulated by RFPA2D and FLAC3D software. Besides that, the numerical simulation results are compared with the results of the experience formula of coal floor damage depth. The research results indicated that,the numerical simulation results are consistent with the results of experience formula.

Key words: Mining-induced fissure, Damage depth, Damage evolution regularity, Numerical simulation