地铁振动下基础隔振效应的实测与分析

Base Isolation Building Response to Subwayinduced Vibration and Its Analysis

摘要:

对地铁附近的装有隔振支座的建筑物进行振动实测,获得了在地铁振动下基础和地下室地面的振动加速度时程记录.先在时域内,分析隔振后加速时程的变化,得到隔振的大致效果,然后计算出相应的傅立叶谱和1/3倍频程谱,可以得到隔振后振动在各个频段上的变化.在此基础上讨论隔振装置对地铁的振动传播的影响.结果表明:地铁运行引起的主要振动分量在45～75 Hz,隔振装置对地铁振动水平分量的隔振效果显著,而对垂直分量有放大作用.

Abstract:

Vibration was measured on the buildings with the installed isolation bearings in the vicinity of subway,the records of timehistory vibration at foundation and basement were obtained .In the time domain,the changes of acceleration timehistory were analyzed after isolation,the general effect of isolation was obtained.After calculating the corresponding Fourier spectrum and one third octave band frequency spectrum,the changes of vibration were obtained in various frequency bands after the isolation.Then the effect of base isolation on the transmission of subwayinduced vibration was discussed.Results show that the main components of subwayinduced vibration are in the frequency domain from 45 to 75 Hz.The isolation effects of isolation device are notable in horizontal direction of subwayinduced vibration,but things are different in the vertical direction.