Study on the dynamic performance of the vehicle-ballastless track system subjected to dislocation of fault zone

China's High-speed railways are now being constructed on a large scale in the complex mountainous regions of the West. However, due to the large number of active fault zones (AFZs) in western China, track structures inevitably need to be laid in fault zones. To understand the impact of small fault dislocations on the mechanical behavior of vehicle-track interaction in the elastic region, this paper establishes a vehicle-track-soil dynamic model. This model employs a novel iterative algorithm to describe and compute the static deformation of the track induced by the AFZ. Besides, the additional deformation of tracks is treated as the e of the vehicle-track-soil interaction system, for depicting its dynamic effects on the interaction system. The validation and an illustrative case are implemented in numerical studies, which demonstrate the effectiveness of the proposed model. The analysis results indicate that the dynamic performance of the vehicle-track interaction system in the vertical direction deteriorates obviously subjected to the dislocation of fault. The high stiffness of slab tracks exacerbates their vulnerability to fault-induced deformations, particularly for the phenomenon that large localized tensile stress occurs under the moving vehicle load. Moreover, the laying angle of the ballastless track is also a significant factor that degrades the performance of the vehicle-track interaction system subjected to fault dislocation, an aspect overlooked in previous research related to railway foundation deformation.