Theoretical Prediction Research on the Creep Camber of the Prestressed Concrete Simply Supported Girders in High-Speed Railways

Using a prestressed concrete simply supported girder (PCSSG)-the China Railway Track System Type Ⅱ (CRTS II) ballastless track system (girder-track system) as the research object, a method for calculating the creep camber of the PCSSG from the anchorage moment of prestressed tendons to the service stage is proposed. The mean value and the 95% confidence interval of the creep coefficient were obtained using the Latin Hypercube Sampling (LHS) method, with concrete strength, ambient relative humidity, and tensile age taken as random parameters. Furthermore, the mean value and a 95% confidence interval of the mid-span creep camber (MCC) of the PCSSG were obtained. In addition, the long-term deflection of the girder-track system was simulated using ABAQUS finite element software. Subsequently, the theoretical, finite element, and measured results of the MCC of the PCSSG were compared to verify the reliability of the theoretical method. A comparison between the MCC of a standalone PCSSG (where a uniformly distributed surface load was used to replace the ballastless track) and that of the PCSSG in the girder-track system shows that the CRTS II ballastless track has a restraining effect on the long-term deflection of the PCSSG.