Vertical Vibration Measurement and Analysis of Buildings on Metro Train Platforms

Vertical vibration tests are performed on two typical multi-floor buildings built on platforms of underground subway and surface subway line,the responses of buildings are analyzed by means of acceleration sat the measured points and their power spectra and transfer function.Finally,environmental level is indicated according to vibration level.Analytical results shows that the multi-floor building vibrates as a whole body when it is subject to train-induced excitations,the vibration frequency range is below 70 Hz.For the building along underground line,it can be clearly seen that there is a obvious enhancement of vibration level as the floor increases from the base to the fifth one and the vibration levels are same from the fifth floor to the top one,the vibration frequency range is 10~30 Hz.The response of the buildings on the surface subway line is different,the vibration frequency range is 40~70 Hz and the vibration of the top floor is more intensive than other floors.Though the vibration induced by surface line stronger than that by underground line,the vibration levels are both below the thresholds of environmental standards.In China,there is little information on the buildings built along surface subway lines,more studies should be done.