Study Of The Vibration And Structure-borne Noise Of The Viaduct In Urban Rail Transit

With the rapid development of economy and increasing population density, cities grow bigger and bigger, elevated rail transit occupies a more and more important role in the urban rail transit construction. The vibration and noise caused by the elevated rail transit has caught people’s attention more widely.This paper firstly systematically sums up the evaluation factors of noise, clarifies the urgency of establishing a complete assessment for vibration and noise of the urban rail transit by comparing the evaluation criteria of the United States with our country’s and then puts forward the recommendations for improvement and establishment of the new standard. Because the low frequency noise radiated by the vibration of the structure can harm the human body with not easily detected and there are few study results on this field, this paper puts emphasis on the theoretical analysis and numerical calculation on the vibration and structure-borne noise of the viaduct. The calculation of the structure-borne noise is a boundary value problem, so the boundary element method has irreplaceable advantages. The acoustic BEM includes the method of frequency domain analysis and time domain analysis. In this paper, based on the finite element-boundary element theory, combining the software ANSYS with the transient acoustic boundary element module of acoustic software Virtual.Lab Acoustics, the vibration caused by the elevated rail transit and the structure-borne noise are simulated and calculated. A three-span continuous box beam model is used in this paper, with train passing bridge simulated as a moving load or a moving mass-spring system model. Then the dynamic response and the noise radiated by the vibration are calculated and analyzed. The vibration displacement response obtained in ANSYS is taken as boundary condition for calculating the outer sound field. The relationship of vibration and noise and the propagation and attenuation law of noise are studied through the time history analysis and spectrum analysis. It can come to this conclusion that the noise can be calculated accurately with the vibration properly simulated. In addition, the influence study is made by changing the bridge parameters and vehicle parameters, which can provide a numerical basis for the control of vibration and noise.