Influence of Different Structural Systems on Rail-Suspension Bridge Interaction

The purpose was to reveal the law for the interaction between a long-span bridge and the rails. A long-span suspension bridge was investigated, (130 + 1060 + 90) m with steel truss girder on double ballasted tracks. A refined finite element model was established for the interaction between the long-span suspension bridge and the track. Three types of tower beam structures were set up, including consolidation system, semi-floating system and floating system. These three structural systems of the super span suspension bridge were discussed as to their influences on the mechanical characteristics of the continuously welded rail (CWR) track. The consolidation system resulted in a maximum longitudinal rail displacement of 272 mm, not conducive to the stability of the system; the floating system led to a vertical bridge deflection of 1/150, which exceeded the allowable value; the semi-floating system had relatively small influence on the overall stress and deformation; therefore the semi-floating system are better than the other two systems. Bridge tower style exerts great impacts on the stress of bridge tower, but has little influence on the stress and deformation of steel rails. Semi-floating system reduces the internal structural force, induced by temperature load; it reduces the displacement of bridge tower, induced by vertical load; and it restraints the vertical displacement of steel rails, and governs the shear force of bridge tower, induced by train braking.