Study On Prediction Of Vibration And Re-radiated Noise In Buildings Caused By Subway Trains

With the rapid development of the subway construction in the major cities and the increasing requirements of urban living environment of urban residents. Vibration and re-radiated noise in buildings caused by subway trains has gradually attracted A lot of research about this question has been done by scholars at home and abroad. Aiming at Vibration and re-radiated noise in buildings,we test vibration and re-radiated noise in a building which located around the Line 15 of Beijing Subway and analyz the distribution of vibration and re-radiated noise in the building.the 3D finite element model and boundary element acoustic model of structure were established by mumerical method and the vibration and re-radiated noise in buildings caused by subway trains were simulated using the model.Finally, analyze the reduction of the vibration and re-radiated noise in buildings by isolation barrier. The main works and summary are as follows:(1) Reviewed and summarized the reseach status and methods of the vibration and re-radiated noise in buildings caused by subway trains at home and abroad. Introduced the evaluation index of vibration in the buildings and re-radiated noise and the evaluation standard in our country. Theoretical and computational methods for building vibration and re-radiated noise were briefly summarized(2) Test vibration and re-radiated noise in a building which located around the Line 15 of Beijing Subway,Arrang a plurality of measuring points in the building and test the distribution of vibration and re-radiated noise in the building. Analyze the index of time-histories、spectrum,1/3-octave spectrum, Z vibration level, A sound level of the data. The test results show that the vibration in the center of the floor is greater than the corner and the re-radiated at the higher height is greater than the lower in the same floor.the vibration and re-radiated noise in the building have a decreasing trend with the floors increasing.(3)A track-tunnel-soil-building 3D finite element model was established by software ANSYS.The vertical acceleration of line 15 rails were converted to wheel-rail force by program. Taking wheel-rail force as the external excitation of model, calculate the vibration response of the building caused by Subway trains and compare the calculated result with the vibration test data.(4)A building boundary element acoustic model was established by Virtual. Lab.Taking vibration of buildings calculated by finite element model as the boundary conditions. Calculate re-radiated noise in buildings by direct boundary element method and compare the calculated result with the re-radiated noise test data.(5) use the filled ditch to reduce the vibration and re-radiated noise of the building.calculate the virbration and re-radiated noise in the building with the filled fitch caused by subway trains,using the finite element model and the boundary element acoustic model..evaluate the effect of the filled ditch by reduation of the vibration and re-radiated noise in the building. The calculate results show that the filled ditch has a good effect on the reduation of the vibration and re-radiated noise in the building...