Study On The Noise Of The High-speed Railway Integrated Stations Caused By The Running Trains

Railway is the national economic artery,critical infrastructure and major livelihood project,and its status and role in China’s economic and social development is crucial.Higher speed is one of the main development directions of Chinese railway.By the end of 2017,China’s high-speed railway has reached 25,000 kilometers,and China has the most modern railway network and the most developed high-speed railway network in the world.In order to strengthen the railway constructions,the government has staged a series of policies to encourage railway comprehensive exploitation and utilization of land in railway stations and along the lines,and the exploitation revenue can be used to support the further development of the railway.At present,comprehensive development of the land surrounding the stations is the focal point,during which the noise influence may be one of the bottlenecks restricting the development.The paper includes nine high-speed railway stations’ noise research results,according to the noise exposure characteristics and the subjective survey results of passengers,and from the aspects of disturbing level and annoyance level of language communication,the allowable limit value and encouraging limit value of reverberation time in waiting hall,platform layer and other areas are put forward.In addition,the indoor noise limit values or sound insulation requirements of commercial houses,offices,hotels,residences,schools and hospitals are determined.The typical elevated station’s noise distribution and characteristics are studied,which shows that,noise influence is greater when the waiting hall is below the railways than above the railways.the platform near the main track is significantly influenced by the trains’ passing-by noise,which can be greater than the allowable limit value of 100 d B(A);the passing-by noise is broadband,the frequency component of 500 Hz to 4000 Hz is the main contribution to the total A-weighted sound level,while the maximum noise level usually appears in the low frequencies from 25 Hz to 125 Hz.Based on the acoustic wave theory,the directivity of high speed railway’s noise,the simulation of high-speed railway noise source and its characteristics,a mathematical model of high speed railway noise prediction has been built.In the model,the high-speed railway noise sources in vertical from down to up are assigned into the wheel/rail area,the body area,and the pantograph area.Noise sources in the wheel/rail area are regarded as dipole sources,noise sources in the body area are regarded as plane sources,and the noise sources in the pantograph area are regarded as spherical sources.The most important parameters of the model are the sound powers of each area.The model has been verified by field measuring data,and the differences between the measured values and the predicted values are all within0.5 d B(A),which confirms the validity of the model.Based on the verified prediction model,the noise spatial distribution of the surrounding area is predicted and studied when the high-speed trains passing through the typical elevated station.The sound level distribution is related to the scale of the station and the height of buildings around.In general,the noise level of the first row of buildings below and near the elevated stations is relatively high,the daytime level and the night level are usually above the limitation values of 60 d B(A)/50 d B(A)even the barriers are applied along the lines.During the comprehensive development of high-speed railway stations,the reasonable layout of buildings with different functions and application of noise control techniques such as barriers and sound insulation windows should be considered to reduce the influence of the noise,and make the noise around meet the requirements of limits.The research results above can provide theoretical and data support for the research of noise control problems in programming and designing high-speed railway comprehensive stations.