Additional Longitudinal Expansion Force between Continuous Welded Rails and Extra-Long Continuous Bridges of High-Speed Railway

In order to investigate the additional expansion force of continuous welded rails (CWR) on extra-long continuous bridges of high-speed railways, the integrative spatial finite element model of track-bridge-pier system is established with the nonlinear spring element simulating the longitudinal resistance between track and bridge. In this paper, the influences of several parameters to the additional expansion force of CWR are studied, including the different resistance models, the number of main spans, the arrangement of adjacent bridges as well as the pier's longitudinal stiffness. Some conclusions are drawn through comparisons and analysis, which could provide valuable references for design and application of long-span continuous bridges on high-speed railways.