地铁列车振动对精密仪器影响的预测研究

以北京某新建地铁线路近距离经过某科研单位为研究背景，对现况道路边和实验室内仪器实验台面的环境振动进行了测试和评估；利用了现场实测与数值模拟相结合的预测方法，该方法考虑了建筑结构、实验台在不同频段下的振动衰减或放大作用，并在1/3倍频程频域下与国际通用的精密仪器防振要求进行比较。采用周期性有限元-边界元耦合方法预测了列车对自由场地的动力响应。基于实测振动响应传递比曲线将楼外振动响应折算到实验台面上，以此评价地铁列车振动对精密仪器的影响。研究结果表明：1）现况道路车流对实验台水平方向振动较大，应采取相应被动隔振措施；2）当列车低速、匀速通过时，振动对仪器影响较小；3）车速大于60km/h匀速通过时，应采用较高级别的减振轨道以确保仪器正常工作。

Prediction of influence of metro trains induced vibrations on sensitive instruments

As a new subway route was planned to be close to a research building in Beijing, subway train-induced vibration will probably be effect to the sensitive instruments in future. To predict the vibration influence on these instruments after subway open to operation, environmental vibration on roadside and sensitive instrument tables were tested. The prediction method that combined field tests and numerical simulation was chosen, by which vibration attenuation or enlargement caused by structure and test tables in different frequencies can be taken into account. A coupled periodic FE-BE method was used to predict field dynamic response caused by subway trains, and the influence on sensitive instruments was predicted as well based on vibration transfer ratio which was calculated from environmental vibration data. Results show that,1) environmental vibration induced by road traffic is harmful to instrument and passive isolation measures on transverse direction should be taken; 2) with a low speed, subway train-induced vibration has little effect on instruments; 3) with a uniform speed over 60km/h, some measures for track vibration should be taken.