清华大学精密仪器环境振动影响评价

清华大学东配楼内安装有多台精密仪器,为预测将来地铁15号线产生的振动影响,对该楼内、外的环境振动进行了现场测试(包括垂向和两个水平向的振动加速度、速度),分析和评价了铁路、地铁、公路产生的环境振动现状对精密仪器的影响和地面振动传播规律.当京包铁路、地铁13号线有列车通过时,三方向振动水平均不能满足Titan、Tecnai、JEM电镜和原子力显微镜的使用要求.当铁路和地铁均无列车通过、但存在公路交通时,Titan电镜垂向和南北水平向振动水平不能满足要求,但东西水平向满足要求;JEM电镜东西水平向振动水平轻度不满足要求,垂向和南北水平向满足要求;Tecnai电镜和原子力显微镜三方向均满足要求.楼外地面垂向和东西水平向的振动加速度峰值和有效值均随振源距离的增大而衰减,在距京包铁路200 m以外衰减逐渐趋缓.但是东西水平向振动(40 Hz以上)在距京包铁路约50 ～80 m范围存在放大区.

Assessment of Environmental Vibration Impact on Precision Instruments in Tsinghua University

Some precision instruments are installed in East Annex of Tsinghua University, to predict vibration impact of metro line 15 in the future. Field test for environmental vibration inside and outside East Annex of Ts- inghua University （including vertical and two horizontal vibration acceleration and velocity） is performed. This paper analyzes and assesses actually environmental vibration impact on precision instruments caused by railway, metro and road traffic and propagation laws of ground vibration. When train passing Beijing-Baotou railway or/ and metro line 13, three-dimensional vibration magnitude can not meet the requirement of Titan, Tecnai, JEM TEM and AFM. Without train and metro passing but only road traffic, east-west horizontal vibration magnitude can meet the requirement of Titan TEM, but vertical and south-north north horizontal vibration magnitude can meet the requirement of JEM horizontal can not. Vertical and south- TEM but east-west horizontal can not. Three-dimensional vibration magnitude can meet requirement of Tecnai TEM and AFM. The peak and r. m. s. values of vertical and east-west horizontal ground vibration acceleration attenuate with the increase of distance to vibration sources and gradually slow down when the distance to Beijing-Baotou railway longer than 200 m. How- ever, there is an amplification region of east-west horizontal vibration （ above 40 50 ~ 80 m away from Beijing-Baotou railway. I-Iz） within the range of about