Safety and comfort assessment of a train passing over an earthquake-damaged bridge based on a probability model

After an earthquake, a track-bridge system may suffer damage and residual deformation, posing a threat for trains passing over a bridge. However, since railway transportation is an important channel for disaster relief, the timely passage of trains is of great significance for the transportation of materials and personnel. In the past, subjective and experience-based judgments were made on whether a train can pass over an earthquake-damaged bridge, and no relevant numerical calculations were carried out. Therefore, a strategy for the evaluation of train performance when passing over existing bridges after earthquakes was proposed. The strategy considers the randomness of track irregularity, and evaluates the running safety performance (RSP) and running comfort performance (RCP) of trains passing over existing bridges from the perspective of probability. The probability law of a lateral residual bridge deformation influence on the RSP and RCP after an earthquake was revealed. Finally, the maximum train passing speed which ensures the RSP was recommended.