Abstract: To counter the deformation and failure in shaft excavation process in a coal mine in Shanxi，and taking the hole inspection data of the coal mine as the geological background and 300~400 m underground rock stratum as the research object，3D simulation analysis on the shaft excavation process was made with application of FLAC3D software.The displacement and stress state of the shaft before and after each excavation step at 3 m were calculated to investigate the deformation law of shaft sidewall and bottom.The calculation results showed that the maximum vertical displacement of the shaft bottom heave that appeared at low-strength sandy mudstone with the excavation depth of 60 m was 12.99 mm.The sidewall deformation at mudstone section is larger than that at sandstone during the shaft excavation process and the maximum displacement of the sidewall that appeared at the excavation depth of 24 m was 2.48 mm in horizontal.Stress concentration easily appeared in the contact zone between mudstone and sandstone.Improving the strength of permanent support in mudstone and the boundary of sandstone and mudstone was recommended.These research results have important reference value for the mine shaft excavation.

Key words: Shaft excavation, 3D numerical simulation, Stress, Shaft deformation