Experimental and numerical studies on aerodynamic loads on an overhead bridge due to passage of high-speed train

When a high speed train passes an overhead bridge structure, the aerodynamic forces acting on the structure change abruptly. This train-induced aerodynamic loading should be taken into consideration for the design of overhead structures. This paper reports on the field experiment and numerical simulation conducted in the study of the aerodynamic loads on such a structure. Wavelet transformation was conducted on the pressure measurements to analyse the surface pressure fluctuation characteristics and to identify the pressure distribution in different frequency bands. The numerical simulation adopted sliding mesh technology with the two-equation k–ε turbulence model, and commercial CFD software FLUENT was used. The distribution of pressure and the relationship between the pressure and train speed were analyzed. Results showed that when the train passed under the bridge structure, complex unsteady turbulent flow arose between the train and the structure. This flow should be taken into consideration in the structural design of the overhead bridge structure.