Abstract: Based on results of surface deformation and shaft cracks monitoring of Chengchao iron mine, the damage reasons of East main shaft are analyzed, by ways of numerical simulation; and then the feasibility of continuous use of shaft is discussed. By using post detailed monitoring data of ground and deep rock mass, a mechanical model for toppling failure is established. The relation between shaft’s crack growth and rock mass horizontal displacement and rock zone in East shaft area is discussed. The results show that: damage of the shaft is caused by underground mining. Horizontal displacement of rock mass has vital effact in shaft damage. The distribution of shaft cracks is related to goaf’s location; there are a lot of cracks on the East and West of east main shaft; but south and north are little. Numerical analysis results show that deformation of surface and deep rock mass will further increase along with the mining activities extend to depth; but deformation of deep rock still too small to lead to entire failure. Crack distribution in vertical direction is related to rock engineering zone by comparison.

Key words: shaft, deformation and damage, underground mining, feasibility study, rock zone, numerical analysis