Effect of Pier and Abutment Non-Uniform Settlement on Train Running Behavior

Abstract

Dynamic behavior of running vehicle on bridge is influenced by the attached irregularity of track caused by pier and abutment non-uniform settlement. In order to study the relationship between them, vehicle-track-bridge vertical coupling system dynamic model is established, in which the four-axle car with two suspension systems on independent bogies is adopted, the bridge is simulated with various finite elements. The vehicle components are treated as rigid bodies, assembled with linear springs and dampers. There are totally 10 degrees of freedom, with car body and each bogie having 2 degrees of freedom of vertical and pitching movements, and each wheel-set having 1 degrees of freedom of vertical movement. As one part of track irregularity, the attached deflection is determined by static mechanics. Dynamic analysis uses time domain method, and nonlinear elastic hertz contact theory is adopted in wheel/rail vertical direction, at the same time the wheel/rail deviations can be considered. Based on ballast track and prestressed concrete box girder bridges with 40m span, the homemade Pioneer within 160∼220km/h, pier and abutment non-uniform settlement with 5mm, 10mm and 15mm taking into account respectively, the car body acceleration and Sperling index corresponding to different settlement at various running speed are obtained, which can provide a reference to the practice engineering design of railroad bridge.