STUDY ON NOISE-ATTENUATING EFFECT OF NOISE BARRIERS WITH SPHERE DIFFUSERS IN URBAN RAIL TRANSIT

摘要

Noise-attenuating effect of noise barriers is largely influenced by their structural design.It is of great importance to study on the optimization of the structure of noise barriers with diffusers in urban rail transit system,noise barriers with sphere diffusers are chose to be the object of this study.The finite-infinite element coupling method is applied for calculating insertion loss in the two-dimensional model by ACTRAN whose reliability is proved by comparison with relevant dissertations,that is the calculation result of Muradali A.and Fyfe K.R.in 1998.Also,the roadbed model without noise barrier is verified by the test carried out in Rail Transit Comprehensive Test Line in Tongji University.Afterwards,qualitative and quantitative analyses are separately done for influences of different diffuser spacing and width on noise-attenuating effect of noise barriers with sphere diffusers.Based on the reliability of the roadbed model without noise barrier by using ACTRAN,regular changes can be figured out by verifying the spacing or width of the diffusers on the surface of the noise barriers.To be more specific,noise-attenuating effect can be improved by reducing the diffuser spacing or increasing the diffuser width,which can provide theoretical foundation for standard design on optimizing noise barriers.