Reliability assessment of a curved heavy-haul railway track-bridge system

In such curved sections, parameters of a track-bridge system have significant influences on the dynamic performance of the vehicle, track and bridge. Based on two-stage technique, 3D dynamic behaviors of a curved track-bridge system under heavy-haul train are simulated. The stochastic parameters to which the dynamic responses are sensitive are extracted by means of factorial experimental design, and the response surface methodology is adopted to study the influence of each sensitive random parameter on the probability of the failure of system, and the reliability of track-bridge structure in curved sections can then be evaluated. The results show that 1) the damping ratio and elastic modulus of bridge, and the interaction of the thickness of ballast bed and the elastic modulus of beam concrete are the key parameters affecting the reliability of track-bridge system; 2) when the radius of the curved section is less than 800 m, the lateral failure probability of the track-bridge system is increased rapidly; 3) maintaining good track quality can effectively improve the reliability of the track-bridge system; and the heavy-haul bridge designed according to the 30t standard can satisfy the requirements for the operation of train with 35t axle load.