Vibration And Noise Analysis Of Underground Buildings Based On Hybrid Method

With the rapid development of Urban Rail Transit in major cities in China,the environmental vibration and noise brought by subway has become increasingly prominent,it has brought convenience to people,at the same time,has brought the very big influence to the people daily life work.Therefore,the problem of building vibration and noise caused by subway train operation also needs to be solved urgently.At present,although some researchers have done some research on the problem of low frequency vibration and noise caused by subway with finite element method,however,there are still some limitations in calculation efficiency and accuracy,the frequency range analyzed was mostly limited to 10～ 200 Hz.In this paper,based on the theory of mixing method and the basic theory of Acoustics,a computational model is established by using the VA one acoustic and vibration software.The frequency range is 10 ～ 500 Hz,10 ～ 200 Hz is BEM-FE model and 200 ～500 Hz is FE-SEA model.This not only ensures the accuracy of the calculation,but also improves the efficiency of the calculation.This paper mainly carries out the following aspects of research work:(1)Consulting a large number of domestic and foreign documents on the train vibration and secondary structure noise related to buildings,to understand the current research status,and summarized their research methods,and some problems in the research process.(2)The vehicle-rail coupling model is established by UM,and the time-domain vertical wheel-rail force is calculated,which is converted into the frequency-domain wheel-rail force by Matlab software,then it is imported into the soil tunnel superstructure model built by VA one for solution.the modal and vibration mode of the building structure and the vibration response of the upper structural plate are analyzed.(3)The structural noise characteristics of hotel,parking building and far and near field are analyzed by VA one software,including sound pressure level,sound radiation efficiency,contribution of sound pressure,vibration power and energy analysis,and the change of acoustic characteristics under the conditions of train speeds of 80 km / h,100 km /h and 120 km / h.(4)By analyzing the contribution of sound pressure of all building panels and cavities,the key panel of noise radiation can be found and the acoustic optimization analysis can be carried out.Finally,different acoustic materials,such as sound-absorbing cotton,cotton felt and PU foam,are selected to analyze the noise reduction effect and absorption characteristics of the building interior,as well as the noise reduction effect and absorption characteristics of different thickness of sound-absorbing cotton,so as to provide a reference for the noise reduction of the building interior.