Influence of Movable Bearing Friction Resistance on CWR of Subway Continuous Beam Bridge

［Objective］ When continuous beams are employed in subway bridges, frictional resistance exists at the movable bearings, which may affect the force and deformation of the continuous welded rail (CWR) on the bridge. Therefore, it is necessary to study the effect of movable bearing frictional resistance (MBFR) on bridge CWR. ［Method］ Taken the commonly used large-span three-span continuous beam bridge in subway (spans of 40 m, 64 m, 40 m respectively) as an example, based on the track-bridge interaction principle and finite element theory, the rail-bridge-pier integrated spatial coupling model considering MBFR is established using ANSYS12.0 finite element software. The influence of MBFR on the force and deformation of CWR on the bridge is analyzed. ［Result & Conclusion］ MBFR enhances the longitudinal constraints between the continuous beam bridge and CWR, showing a significant impact on the force and deformation of CWR on the bridge. With the increase of the movable bearing frictional factor (MBFF), the rail expansion force, the rail braking force, the track-bridge relative displacement, and the rail broken gap value all decrease; when MBFF increases from 0 to 0.05, the rail expansion force decreases by 37.18% and the pier longitudinal force at the fixed bearing of continuous beam bridge increases by 2.02 times under expansion condition; under the braking condition, the rail braking force, the track-bridge relative displacement and the pier longitudinal force at the fixed bearing of the continuous beam bridge decrease by 13.74%, 17.65% and 37.73% respectively; under the condition of rail broken, the rail broken gap value and the pier force decrease by 9.01% and 56.90% respectively. It is recommended that the influence of MBFR should be considered in the design of CWR and piers on subway continuous beam bridges.