Model testing on dynamic behaviors of the slab track of high-speed railway

This paper presents a full-scale physical model test on a ballastless high-speed railway's dynamic performance. Both cyclic loading at fixed point at track and simulated train moving loads are used. A portion of ballastless high-speed railway consisting of track superstructure (rails, slab, concrete base) and track substructure (roadbed, subbase and subgrade soil) has been built in a model test box (15m*5m*6m) in Zhejiang University. A sequential loading system composed of eight high-performance hydraulic actuators is developed to exert dynamic loading on slab track at fasteners' positions to simulate train's moving loads. A theoretical model of train-slab track-subgrade dynamic interaction is applied to determine loads acting on fasteners in the experiments. The resonance frequency of the ballastless track system and vibration velocities at track structure show good agreement with the field test. A three-dimensional finite element model is also developed to interpolate the test results from the physical model testing. The influence of train speed on ballastless slab track's dynamic behaviors is clearly illustrated.