Abstract:

During the construction of the shallow loess tunnel, ground surface cracks along the longitudinal direction of the tunnel are often found on both sides of the tunnel which have brought many adverse effects to the loess tunnel project. Hence, the railway tunnel project in Dongzhiyuan region of Qingyang City, Gansu Province is taken as an example to study the temporal and spatial laws of ground surface longitudinal cracks generated by loess tunnel construction. Through the investigation of ground surface longitudinal cracks on site and the numerical simulation of computer, the causes of crack formation are analyzed and the method for determining the development state of longitudinal cracks in model soil are arranged. After analyzing the development status of ground surface longitudinal cracks under different tunnel burying conditions and different time points, the spatial and temporal development laws of ground surface longitudinal cracks are drawn. Finally, the temporal and spatial laws of the ground surface longitudinal cracks in shallow tunnels are summarized, and corresponding countermeasures are proposed.

Key words: loess tunnel, construction, numerical simulation, ground surface crack, development law, prevention