The FEM-Simulation And Experimental Research Of The Noise Filed In The Highway Tunnel

With the development of public transportation, the tunnel-building is rapidly developing. The traffic noise has become an important role of the urban noise pollution. At the same time, the noise problem in highway tunnel has attracted the attention of public.Aiming at the problem of traffic noise in the highway tunnel, the finite element model of the noise in highway tunnel is built with the acoustic finite element method. And the noise tests are done to research the problems about the traffic noise in the tunnel. Firstly, the tunnel acoustic field characteristics with different source attributes are got through the noise tests in the underground test tunnel. On the basis of these results, finish the simulation of the sound field under the same situations with the FEM module of the Virtual.Lab. And do the special research of acoustic field characteristics in the curved tunnel. The consistency of the practical tests and acoustic field simulation is verified by the comparison between measurements and simulated results. Then, some inconvenient tests by simulation are done in a highway tunnel. Through these tests, study the tunnel acoustic filed influence caused by the different motor speed, the different pavement materials, the sound absorption material. Finally, do the statistic and analysis by using R, the statistical programming language, in order to find the rule and relationship between the data. The results will build the foundation of the active controlment of tunnel noise.With the conditions of these tests and simulation, there are some conclusions been gotten through the research. When the source’s vertical position is higher, the sound pressure in the test point is smaller. When the source frequency is 125 Hz, the sound pressure in the car’s position is higher than it in the shoulder’s position 9dB. When the frequency is less than 500Hz, the sound pressure caused by the source in the transverse center is higher than it caused by the sound in the transverse both sides, and the figure is 4dB. Spraying the sound absorption material, the reduction in the shoulder’s position of the noise is better than it in the car’s position. And the sound absorption has a good effect on the middle frequency sound compared with the low frequency sound. For the different curve radius, they have litter effect on the tunnel acoustic filed. When the motors running in the tunnel with the speed between 30km/h to 70km/h, the sound pressure level in the test point will increase between 4dB to 6dB when the speed increasing 20km/h. The YEASPL in the tunnel with asphalt pavement is less than it with concrete pavement 3dB.