Analysis of Influence of Moving Axial Load on Elevated Box Bridge of Slab Track

Due to the increasingly usage of the heavy-load train, the effect of the moving axial load on the noise radiation of elevated bridge structure should be concerned. In this paper, high speed train-track-bridge coupled model is established, and the train axle load, which is taken as the boundary condition of the load, is applied to the finite element model of elevated box bridge structure to calculate the vibration response of the surface of a box bridge. In this model, the vibration response is taken as the acoustic boundary conditions and is added to the boundary element model of elevated box bridge structure to study its sound radiation. The results show that the plate-shell unit can well reflect the overall and local vibration characteristics of the bridge structure, and under the effect of moving axial load, the vibration frequencies of box bridge structure concentrate in 0–300 Hz and the main peaks are in 10–160 Hz; the finite element-boundary element method can effectively analyze the low frequency noise radiation of box bridge caused by the moving axial load; the most of structure noise induced by moving axial load is below the audible range of which the noise is greatly harmful to human body, thus it must be taken seriously.