Abstract: In response to such complex conditions as extremely broken rocks, one thousand meters depth, and large size section of new auxiliary shaft ingate in Haizi mine in Huaibei city, shaft ingate rock stability has been analyzed by ABAQUS finite element numerical software for original support design scheme, and distribution law of displacement field, stress field, plastic zone of ingate surrounding rock and mechanical characteristics of ingate supporting structure have been shown. The supporting structure design of ingate has been optimized according to numerical analysis result. Ingate primary supporting structure is composed of bolt, steel mesh, shotcrete and anchor. Ingate secondary support is composed of whole section steel fiber reinforced concrete lining with bottom arch, floor grouting bolt and floor anchor. Strength grade, steel fiber incorporation rate and the optimal mix of steel fiber reinforced concrete have been determined through laboratory tests. Field monitoring results show that ingate supporting structure has higher safety reserve and the design optimization is reasonable.

Key words: ingate, rock stability, numerical simulation, supporting structure optimization