Deformation Control Standards of Urban Rail Transit Long-span Beam Bridge Based on Operation Safety Performance Evaluation

Drawing on the concept of circular curve centrifugal acceleration and referring to the track dynamic quality tolerance management limits, taking the rigid frame bridge and the continuous beam bridge as the practical cases, vehicle-track-bridge coupling dynamic analysis is conducted. Firstly, the vehicle dynamic response under no initial deformation condition is analyzed, the difference between which and the car body acceleration in the management standard is found, and the allowable deformation limit of the bridge is primarily determined. Then, considering various load conditions and track geometry irregularity, the vehicle-bridge dynamic response analysis is carried out in order to verify and correct the final conclusion. For long-span beam bridge, research results show that: to satisfy the vertical deformation requirement, the driving safety limit of the total torsion span ratio is 1/750, the warning limit is 1/1 050; to satisfy lateral deformation requirement, the safety limit of total torsion span ratio is 1/1 500, and the warning limit is 1/2 500. The safety limit of rotation angle at bridge end is 5%, and the warning limit is 3.5%; the safety limit of beam torsion vertical deformation difference is 10 mm, and the warning limit is 8 mm.