Study On Noise Impact Assessment And Noise Reduction Measures Of Urban Rail Transit

With the rapid growth of social economy and the rapid development of the city,urban rail transit has gradually become the preferred means of transportation for the people to travel,with its unique advantages-convenient,fast,safe,comfortable and punctual,which provides continuous impetus for the rapid development of the whole city.But rail transit brings happiness to the city and people,at the same time,it also brings noise pollution to the city and people.Through the combination of theory and practice,this paper carries out a series of studies on the impact assessment and noise reduction measures of rail transit noise in Chongqing from five aspects: Firstly,by consulting the noise-related documents,the related concepts of rail transit noise,the evaluation criteria of noise,the characteristics of rail transit noise and so on are carried out.All-round elaboration will pave the way for further theoretical study of rail transit noise in the future.Then,taking the noise of Qiansimen Bridge on Line 6 of Chongqing Rail Transit as the research object,the actual noise of the bridge during the day and at night is monitored experimentally.By comparing the monitoring results with the 4A category of "Acoustic Environmental Quality Standard"(GB3096-2008),it can be seen that when there are trains passing,the outdoor noise exceeds the prescribed standard.Then,the site survey of Qiansimen Bridge on Line 6 of Chongqing Rail Transit is carried out,and the sources of noise are analyzed.It is known that there are three main sources of noise and vibration of Qiansimen Bridge,among which the noise mainly comes from wheel-rail noise and vibration when the train passes through;at the beginning of construction of Qiansimen Bridge on Line 6 of Chongqing Rail Transit New and effective noise reduction measures are put forward by comparing and analyzing the noise reduction measures in the period.A 150-metre vertical fully enclosed noise barrier is installed on both sides of the Qiansimen(Nanguo Lijing Section)track.The comprehensive noise reduction estimate is about 15 d B.The calculation of the sound barrier column is carried out by using MIDAS CIVIL software,etc.The results show that the sound barrier is installed.Barriers will not cause potential safety hazards to the structural performance of the bridge,which are in line with the national standards.Secondly,using ANSYS finite element analysis and CFD numerical simulation methods,the wind resistance and driving safety of Qiansimen Bridge on Chongqing Rail Transit Line 6 are studied and demonstrated.The results show that the installation of fully enclosed sound barrier has no effect on the wind resistance and driving safety of Qiansimen Bridge.Finally,the process flow,the original scheme,the steel framework and the installation scheme of the sound barrier in the dismantling and installation of the sound barrier of Qiansimen Bridge are elaborated,which will provide some theoretical and technical support for the practical project of noise reduction of rail transit in the future.