ABSTRACT In cold‐region railway tunnels, the lining is subjected to multiple types of loading, which may cause existing cracks to propagate and threaten operational safety. In this study, a three‐dimensional load‐structure model of the tunnel lining is developed based on finite element method (FEM). Stress intensity factors (SIFs) are used as the evaluation index to investigate the crack propagation behavior under moving train loads and frost‐heaving forces induced by water ponding behind the lining. The results show that although cracks at the sidewall experience the highest SIFs, a single moving train load does not trigger crack propagation. The SIFs increase with both the length and depth of the crack, indicating that large‐sized cracks are more inclined to propagate. Under frost‐heaving forces, the propagation risk is highest at the crown, followed by the haunch, and lowest at the sidewall. At the crown, even a relatively small ponding area (0.9 m 2 ) can lead to crack propagation. The SIFs increase with the crack length and decrease with the crack depth in depth direction. The results can provide references for maintenance prediction of railway tunnel in cold regions.
Chen et al. (Thu,) studied this question.