Dynamic performance of a deep buried pile-plank structure transition section for a high-speed railway—Field tests and numerical analyses

Abstract

The dynamic performance of a bridge-tunnel transition section with a deep buried pile-plank structure (DBPPS) for short transitions was studied. Field tests were performed, analyzing accelerations, velocities and displacements in the track and subgrade. Based on the field test results, the influences of the train types, driving direction and running speed on the dynamic response in the transition zone were investigated. A 3D finite element model considering vehicle-track-subgrade coupled interactions was presented, and the results from the model were compared with the measured responses. Based on the model, the distribution of the vertical dynamic stress in the subgrade was analyzed, and the running quality for the comfort of passengers on the train and the dynamic response along the DBPPS transition zone with alternative fillings in the subgrade, such as graded gravel and AB group filling (well graded coarse-grained soil with less than 30% fine-grained soil), were discussed. Comparatively, the graded gravel is recommended for the filling of base layer in the DBPPS subgrade.