Deformation Failure Mechanism of Deep Vertical Shaft in Jinchuan Mining Area

Vertical shafts play an important role in the safe operation of mines. The stability of vertical shafts has always been a difficult problem in mining engineering, especially with the increasing of mining depth. In order to keep the engineering works stable, it is necessary to make the deformation failure mechanism of vertical shafts clear. This paper describes a case study of the deformation and failure mechanisms of the vertical shaft in Jinchuan No. 2 mining area in Gansu Province, China. Long-term deformation trends and characteristics of the vertical shaft are analyzed through ground movement and GPS monitoring of ground fissures. Then, based on previous research experience and a detailed field investigation, the modes, influencing factors, and mechanisms of deformation failure in the vertical shaft are studied. To further investigate the mechanism of shaft deformation failure and damage process under mining, the Universal Discrete Element Code (UDEC) software with Trigon approach is employed to build the numerical model of the vertical shaft. Through displacement, stress, and damage analysis, the time, location, and cause of vertical shaft failure during mining are explicitly illustrated. The results suggest that the upper and lower parts of the fault are activated in different ways. The damage to the vertical shaft is still developing at a very high rate under mining with filling method. All our results throw light on the nature of deformation and failure of vertical shafts, and several suggestions for the engineering of deep vertical shafts are finally put forward, providing a reference for other engineering.