Evaluation of longitudinal connected track under combined action of running train and long-term bridge deformation

摘要

With long-term operation of high-speed railways, bridge deformation is hard to avoid, which directly affects the mechanical property of longitudinal connected track. To ensure the structural stability of longitudinal connected track and operation safety of train, this work proposes a work to evaluate longitudinal connected track under combined action of running train and long-term bridge deformation. First, the methodology of evaluating longitudinal connected track subject to train load and long-term bridge deformation has been proposed, in which an accurate train-track-bridge dynamic model and the method to determine long-term bridge deformation are settled. Then, the long-term bridge deformations caused by concrete creep, shrinkage, temperature, and pier settlement are investigated. On this basis, the evaluation of longitudinal connected track subject to long-term bridge deformation and running train is conducted, and the safety value of pier settlement for Chinese high-speed railways with longitudinal connected track is suggested. Results show that the long-term bridge deformations are even larger than the amplitude of random rail irregularity. With smaller settlement, influences of creep, shrinkage, and temperature play the leading role in affecting the mechanical behavior of longitudinal connected track, while influence of pier settlement occupies the dominant position with larger settlement. It is suggested that the pier settlement for Chinese high-speed railways with longitudinal connected track should be less than 7.7 mm to ensure structural stability of track and operation safety of train.