A New Bilinear Resistance Algorithm to Analyze the Track-Bridge Interaction on Long-Span Steel Bridge under Thermal Action

Abstract

In this paper, an analytical algorithm, based on the bilinear resistance model, was proposed to analyze the track-bridge interaction on long-span steel bridges under thermal action. Calculation results show that the proposed algorithm is more accurate than previous analytical algorithms and can achieve nearly the same accuracy as the finite-element method (FEM), but is more efficient than FEM. Based on the algorithm, this paper explained why the longitudinal force (LF) in the middle of the bridges doesn't increase as bridge length increases, then proposed a manual LF calculation formula. Researchers and engineers can use this formula to easily estimate the maximum LF on bridges which have rail expansion devices (REDs). A parametric study was performed. The result shows that LF is not a matter of concern on the bridges with REDs. Besides, the relationships between track resistance distribution, track-bridge relative displacement and boundary conditions were revealed, and the difference between LF on bridge and on embankment were discussed. The outcomes of this paper can be applied to long-span centrosymmetric continuous bridge as well as cable-stayed bridges.