Abstract：Pier settlement is unavoidable for high-speed railways, directly causing the nonlinear contact behavior between longitudinally-connected-track and bridge deck and further affecting the dynamic performance of running train. Aiming at this problem, this work firstly studies the mechanism of contact between track and track. Then, based on the train-track-bridge dynamic interaction theory, a methodology is proposed, and the nonlinear contact behavior between track and bridge is investigated. Finally, the track stiffness caused by contact behavior and its influence on running train are determined. Results show that, there are three gaps between track and bridge. The upward movement of adjacent pier caused by the settlement pier is much smaller than the settlement at the settlement pier location, while the influence of pier settlement on upheaval region can’t be ignored. The longitudinal connection characteristics of track can alleviate the train vibrations to some extent.
