Dynamic modelling of a high-speed train-track-mountain tunnel interaction system: A case study with tunnel dislocation in an active fault zone

In this work, a high-speed train-track-tunnel interaction model is established on the basis of vehicle-track coupled dynamics and coupling of the structural elements. Compared to previous work, an emphasis is put on the modelling of the mountain tunnel composed of multiple arcs, and a convenient double track-tunnel coupling strategy based on the spatial symmetry of track configurations in the tunnel is proposed. Considering the tunnel dislocation in the active fault zone, a deformation mapping method to achieve the displacement transmission from the soil to the track and tunnel structures is presented, and then the influence of fault dislocation, considering train speed, single- and double-train operation, on system dynamic performance has been calculated and analyzed. It is concluded that tunnel dislocation shows significant dynamic influence on train running quality, and the train running speed, fault dislocation amplitude and width should be analyzed cooperatively.