Noise Barrier Performance Of High-speed Track And Primary Investigation Of Its Reducing Load Techniques

Noise barrier is one of the most effective measures to reduce the noise of high speed trains. It is widely used on high-speed tracks which develop fast in China. The aerodynamic impulse pressure of high-speed trains has a strong effect on noise barriers as trains pass by them. The connections between two neighboring units and the bolted joint on the base may suffer fatigue damage. The impulse pressure increases with the train speed increasing, which leads the lifespan of the barrier to be shortened. In order to insure the operation safety of high-speed trains, it is necessary to explore the load reducing techniques and application of the noise barrier. The main work and conclusions are as follows:This paper, based on the theories of computational fluid mechanics and computational dynamics, develops a numerical model to study the aero-dynamical behavior between a high-speed train and the noise barriers installed on the track sides when the train passes by the noise barriers. The reliability of the numerical results is verified. The transient aerodynamic pressure on the wall of the noise barrier is calculated. The impulse pressures and dynamic responses of the barrier in different cases are compared. It is found that the pulsating wind pressure distributions of the barrier are quite close in the different cases and the peaks of the pulsating wind pressure and their locations are a little different. In the analyzed cases, the resonance of the barrier does not occur.The paper carries out a preliminary discussion on the mechanical performance evaluation method of the noise barrier. Based on the fatigue theory, the relative reduction in the composite aerodynamic force amplitude of7newly designed barriers, compared to noise barriers with up-right wall, is used as the criterion to evaluate the mechanical performance of the new designed barriers. The effect of structural parameters of the noise barrier on louver form is analyzed in detail, which shows that the aperture size of the louver has a great influence on the load reduction of the impulse pressure.The further research on the reduction in the aero-dynamical loading on the noise barrier is under way. Lacking of theory and test in this field needs large amounts of follow-up explorations.