Research On Prediction And Control Of Wheel-rail Noise In High-speed Railway Bridge

With the development of the times,the scale of China’s high-speed railway is gradually expanding.In the process of high-speed railway construction,the problem of railway noise has become increasingly prominent,which affects the normal life of residents.At the same time,with the continuous maturity of bridge technology,the emerging trough girder has unique advantages in function,which can reduce vibration and noise,but it has not been widely used in high-speed railway bridges.This paper takes wheel-rail noise,which accounts for the main part of high-speed railway noise,as an example,and takes the simple-supported box girder and trough girder as the research objects to explore the influence of changes in beam form and cross-sectional parameters on the sound field of wheel-rail noise.The applicability of trough girder is improved in high-speed railway.The main research work and conclusions are as follows:(1)A attenuation formula for the propagation of wheel-rail noise sources in the air was established.Based on the standard sound source library,the noise source of the original 300km/h wheel-rail was corrected,and the sound pressure level attenuation curve was calculated using SYSNOISE.According to the principle of data fitting,a new acoustic attenuation formula related to different frequencies and horizontal distances was established,and the error was small compared to the calculation result using SYSNOISE.(2)A sound source promotion method was established based on the wheel-rail noise source under the original speed level.According to the principle of acoustic energy,the relationship between sound energy and speed and frequency was obtained,and the noise source of wheel-rail noise at speeds of 280 km/h and 320 km/h was promoted.On-site testing was carried out on the beam bridge of a high-speed railway,and a calculationmodel of box girder sound field was established based on SYSNOISE’s two-dimensional boundary element method,and two promotional sound sources were used as input conditions to calculate the wheel-rail noise field of the box girder.The correctness of the calculation method and the validity of the sound source promotion method were verified by the comparison between calculation and measurement.(3)A wheel-rail noise calculation model for trough girder was established.On the basis of the verification of the correctness of the acoustic calculation method,a wheel-rail noise calculation model of the trough girder was established.The noise field of wheel-rail noise on the side of the trough girder was analyzed,the effects of different pier heights and different driving speeds were discussed,and the noise field of wheel-rail noise of the box girder was compared.The increase of pier height was beneficial to the noise reduction effect of field points on the beam side,while the increase of driving speed was unfavorable to the noise reduction effect of field points on the beam side.Compared with box girder,the noise reduction effect of the trough girder was better and its applicability was better.(4)The noise reduction effects of cross-sectional parameters and sound barrier of the trough girder were analyzed.Based on the principle of low noise,the noise reduction design of the trough girder was carried out from two aspects.The wheel-rail noise calculation model of the trough girder with different section parameters and the wheel-rail noise calculation model of the trough girder with different forms and parameters of sound barrier were established,and the comparison was made with the box girder with sound barrier.The sound pressure level increased with the increasing of the thickness of the web and decreased with the increasing of the height of the web.The sound pressure level in different directions had certain differences in sensitivity to the change of the angle of the web.The sound pressure level decreased with the increasing of the thickness of the bottom plate,and its sensitivity to the change of the length of the flange was not as good as the above section parameters.After installing sound barrier,the shape of the sound barrier had a significant effect on the noise reduction effect of the trough girder.The height,thickness and location of the sound barrier can be selected within a reasonable range.For the two kinds of beams,the box girder with sound barrier had better noise reduction effect.