Ground loading of shallow tunnels under seismic scenario

Based on the calculation diagram specified by the current codes, the horizontal slice principle and the horizontal seismic coefficient are introduced to establish a general method for calculating the ground loading of shallow tunnels under seismic scenario. Compared with the traditional methods, it can unify the static and seismic scenarios into one single calculation diagram, separate two strength parameters apart as independent factors, and consider the multiple-layered ground condition. The case study of simple ground shows that the separation of cohesion and friction angle can describe the ground loading in a more accurate way. The case study of multi-layered ground shows that the ground condition within the range of tunnel itself plays a key role for the distribution of ground loading. Moreover, the influences of two strength parameters and horizontal seismic coefficient on the rupture angle and vertical ground loading are further analyzed through a series of case studies. The proposed method provides a reliable theoretical basis and technical reference for the anti-seismic analysis of shallow tunnels.