Abstract:

The stratum lithology, surrounding rock structure, asymmetrical load direction and features of the accumulation and development of the deformation of the surrounding rock mass of Jinguashan tunnel are described. In case several unfavorable factors occur at the same time and the deformation accumulates to a certain level, serious rock burst may occur, even if the depth of the cover of the tunnel is far less than the limit value specified in the current standards. The causes for the rock burst occurring in the construction of Jinguashan tunnel, which has shallow cover, are explained.

Key words: Jinguashan tunnel, rock burst, asymmetrical load