Influence of High Speed Railway Noise Barrier Length on Insertion Loss Based on Numerical Simulation Calculation
Noise barriers are currently the most common and effective noise reduction measure for high speed railway.The height of noise barriers is the main design parameter,while the length and position of noise barriers are generally selected according to experience in combination with simple calculation.The influence of noise barrier length and prediction point position on insertion loss change is less considered.According to Kurze point sound source diffraction attenuation theory,the theoretical algorithm of finite length noise barriers on train line sound source insertion loss is derived,and the influences of noise barrier length and height changes on the insertion loss of noise barrier at different prediction points are compared and analyzed.The conclusions of the study are as follows:(1)With the increase of the length of the noise barrier,the insertion loss of noise barrier increases at the location of each prediction point,especially near both ends of the noise barrier;(2)Adopting the measures of heightening and extending the noise barrier has different effects on the insertion loss value and spatial distribution.Therefore,the noise barrier optimization measures shall be reasonably selected according to the position of the prediction points;(3)When the end of the semi-infinite length noise barrier is lengthened by 50m,the area with obvious variation in insertion loss is located within the range of 110m horizontal distance from the end of the noise barrier and 130m distance from the central lines of track.
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