地铁平台上建筑物竖向振动测试与分析

为了分析地铁运营对环境振动的影响,对地铁隧道平台和地面线路平台上多层住宅楼的竖向振动进行了现场实测,从加速度时程、加速度傅氏谱以及加速度幅值传递函数3个方面对实测的数据进行了分析,在此基础上对加速度振级进行了对比.结果表明,地铁平台上多层建筑物竖向振动基本表现为整体振动,以频率低于70 Hz的振动为主;对于地下线路,楼层间信号的放大主要集中在10～30 Hz频段,第5底层以下振动逐层增强,第5层以上振动基本无变化;对于地面大平台线路,结构主要表现为频段为40～70 Hz的整体振动,振动随楼层增加逐渐增强;地铁隧道线路对建筑物的影响较地面线路小,但2者的振级均满足环境规范要求;对于地面线路平台建筑还处于起步阶段,应对其进行专门的评价.

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.