Optimization Analysis Of Sound Barrier Noise Reduction Model For High Speed Railway

As one of the environmental problems in the development of high-speed railway,the impact of environmental noise on the production and life of the residents along the line is increasingly serious.For this reason,various noise reduction measures are applied to high-speed railway.As one of the most widely used noise reduction measures,the actual noise reduction effect of sound barrier often fails to reach the predicted value.In the current noise reduction calculation model,the mono sound source model is used to simplify the model,and the reflection effect of sound wave between the barrier and the vehicle body is ignored.In this paper,based on the above problems and combining the theoretical and practical measurement methods,the calculation formula of the insertion loss of the sound barrier considering the primary reflection sound is derived and the actual section is predicted.The measured results were compared with the predicted results of the formula to verify the accuracy of the prediction formula for the insertion loss of the sound barrier after considering the reflection of a sound wave.At the same time,considering the different speed because of the sound source of change,sound barriers noise reduction effect is affected,but the current study source is determined based on the three source noise prediction gave no grabs than,unable to use the formula to forecast,this paper compared different speed bridge section of the measured noise barrier insertion loss,in order to explore the influence of different speed to the noise reduction effect of sound insulation effect.Secondly,considering that there is a significant difference in the acoustic barrier distance between the inside and outside trains due to the large distance between them,the measured acoustic barrier insertion loss of the inside and outside trains is compared and analyzed to explore the influence of the inside and outside trains on the noise reduction effect of the acoustic barrier.The conclusions of this paper are as follows:1.The insertion loss of sound barrier in bridge segment increases with the distance(15m~45m);2.After the comparison between the measured acoustic barrier insertion loss and theprediction by field test,the calculation formula of the acoustic barrier insertion loss after considering the primary reflection is more accurate than the traditional formula;3.The insertion loss of sound barrier in high-speed section is smaller than that in low-speed section,and the farther the measuring point is from the line,the greater the difference between them;4.The insertion loss of sound barrier of trains running on the inner line is larger than that on the outer line.At the same section,the difference between them is the largest at 30 m and the smallest at 15 m.