Response of prefabricated-polyurethane reinforced ballasted track to dislocation in tunnels through active fault zone

The dislocation of the active fault zone may cause some threat to the track structures passing through it, in order to investigate the response of prefabricated-polyurethane reinforced ballasted track and CRTS III slab track to different forms of fault and to compare their adaptability in fault zone, a finite element model of the track-tunnel-surrounding rock system and a dynamic model of vehicle-track system were integrated together in this study. Based on the models, the changes of track geometry of the two track structures were studied, the mechanical behaviour of track components was revealed, and the effect of irregularity caused by fault dislocation on vehicle dynamic response was studied. Results show that the components of CRTS III slab track are damaged at a smaller dislocation displacement than those of prefabricated-polyurethane reinforced ballasted track. With the increase of the train speed and dislocation displacement, the derailment coefficient and wheel load reduction rate also increase. The safe speed limits for travelling under different types of fault and different dislocation displacements are obtained, which can provide reference for similar engineering applications.