Uncertainty analysis of the long-term deformation of CRTS III slab ballastless track-prestressed concrete simply supported girders

A finite element model was established to study the long-term deformation coordination mechanism of a CRTS III slab ballastless track-prestressed concrete simply supported girder system (girder-track system). Considering the randomness of key parameters, the mean value of the creep coefficient with a 95% confidence interval was obtained using the Latin hypercube sampling method. Secondary development using Abaqus software was used to simulate concrete shrinkage, creep, and relaxation of the prestressed tendons. Subsequently, the uncertain long-term deformation of the girder-track system was analysed in detail. The results indicated that the CRTS III ballastless track significantly increased the mid-span creep camber of the girder (MCCOG). The long-term deformation of the girder causes a difference in vertical deformation between the layers of the girder-track system and induces voids between the base plate and the self-compacting concrete. Additionally, rail irregularities also appear. The deformation amplitude of the rail is exponentially related to time and proportional to the MCCOG with a scale factor of 1.02. Moreover, the small resistance fastener (SRF) can effectively weaken the girder-track interaction.