Abstract：
Collapse is one of the most common disasters in tunnel construction, and its prevention is the focus of safety measures in tunnel construction. In light of the characteristics of surrounding rock deformation, failure, and instability, tunnel collapse events are attributed to surrounding rock instability, structure failure and/or environmental disturbance based on the statistics of typical cases, and the evolution process and formation mechanism of various collapse events are systematically studied. These three types of accidents are significantly correlated to the characteristics of surrounding rock movement and the interaction mode between the supporting and surrounding rock, and these accidents occur at the tunnel face and front, behind the tunnel face before secondary lining installation and at shallow tunnel portals. Comprehensive treatments are suggested with respect to geological surveys, detailed design,enhanced monitoring and construction management so as to avoid tunnel collapses and improve the safety of tunnel construction.
2018, Vol. 55 