Effects of Lateral Dislocation Deformation on Vehicle and Track Dynamics Response Through Active Fault Zones

The mileage of high-speed railway operation in China is increasing year by year, and the laying area is extensive. In the complex and dangerous mountainous areas and other foundation large deformation sections, it is easy to produce lateral dislocation deformation due to faults or large deformation of soft rock, etc., which affects the safety of traveling. In order to study the effect of lateral dislocation deformation on vehicle dynamic response, this paper establishes a vehicle–ballastless track–tunnel coupling dynamic analysis model considering lateral dislocation deformation and analyzes the vehicle dynamic response and rail dynamic performance impact under different lateral dislocation deformation. The results show that the lateral misalignment deformation increases the vehicle dynamic response, the vehicle safety and smoothness deteriorate, and the rail displacement and acceleration increase. At the same time, the long-term service performance of the fastener system further deteriorates, affecting the track geometric position-keeping ability of ballastless track structure. Vehicle and track dynamic response are basically positively correlated with the amplitude of lateral deformation and negatively correlated with the length of lateral deformation. As the lateral deformation length increases, the acceleration curve of car body acceleration gradually transitions from an M-shape to an inverted V-shape. Particular attention should be given to the dynamic response characteristics of the track and vehicle when the lateral deformation length is between 5[Formula: see text]m and 15[Formula: see text]m. During maintenance, it is recommended to focus on track sections with shorter lateral deformation lengths and greater deformation amplitudes.