Research On Vibration Response Of The Building Cover Of A Depot In Hefei Metro

Since the opening of the first subway line in Beijing at the end of 1971,a total of 34 cities in mainland China have opened rail transit by the end of 2017.A total of 165 rail transit routes have been opened and the operating lines have reached 5032.7 kilometers.Hefei Metro has officially opened operations on lines 1 and 2 by the end of 2017.With the rapid development of the subway in the country,the depot covers a large area,the building density is small,and there is a large amount of space in the upper part.In order to improve the comprehensive utilization efficiency of land and the return on investment of the subway,the construction of the superstructure of the depot has also developed more potential in recent years.However,due to the frequent entry and exit of vehicles in the subway depot,and the vibration and secondary structure noise of the superstructure caused by the test line and normal maintenance work,the comfort of the building interior is reduced.Over-track buildings is difficult to meet the national residential vibration and indoor secondary structure noise related standards.At present,the research on the vibration response of the test-line building in China is still in the preliminary stage.Through the analysis of the actual measurement and the results of the model,the main conclusions are as follows:(1)The influence of train vibration on the building of the test bed in Hefei is measured.When the train passes,the vibration response of the over-track building is mainly low frequency vibration below 40 Hz,and the peak is higher than 65 dB.The actual measurement shows that when the train runs at a constant speed of 24km/h,the vibration response peak of the test building is higher than 62 dB.According to the research,with the increase of the running speed of the train,the existing railway conditions will produce vibrations of the following vehicles.It will have a great impact on the living environment of the superstructure.(2)Under the condition of predictive condition,the predicted value of each layer of multi-storey building exceeds 55 dB,and the predicted value of vibration of high-rise building to 7th floor exceeds 55 dB,and the predicted value of vibration to 17 th layer exceeds 50 dB,one to two layers.There is a phenomenon of exceeding the standard.Under the condition of forecast condition 2,the predicted values of multi-story building vibrations exceed the standard limit of 65 dB.The predicted values of the high-rise buildings until the 7-story building room exceed the vibration limit.At night,there are still vibrations exceeding the standard on the 13 th floor.(3)The prediction results and the measured results obtained by the chain formula of the high-rise building and the multi-storey building are analyzed.The train vibration on the main line of the test line is affected by the vibration of the upper cover building when the test condition is 24km/h.When the train is on the test line In normal operation,it will exceed the vibration limit of “Class 1 residential,cultural and educational areas” in “Standards for Building Vibration and Secondary Structure Noise Limits and Measurement Methods for Urban Rail Transit ”(JGJ/T170-2009),and The frequency-divided vibration limit in the Standard for Indoor Vibration Limits and Measurement Methods for Residential Buildings(GB50355-2005).