北京地铁5号线地下线减振措施现场测试与分析

In-situ Test of Vibration Attenuation of Underground Line of Beijing Metro Line 5

为满足沿途多处敏感点的环境振动要求,北京地铁5号线采用了多种减振措施。其中地下线在一般减振、较高减振和特殊减振要求的地段分别安装了普通扣件、Ⅲ型轨道减振器扣件和钢弹簧浮置板轨道。采用高灵敏度加速度传感器,对北京地铁5号线地下线一般减振、较高减振和特殊减振地段进行了现场测试。在时域和频域内,比较了各测试断面钢轨、道床和隧道壁的竖向振动加速度,分析了上述不同措施的减振效果。结果表明：（1）普通扣件能有效地衰减钢轨和道床间的振动传递,但对20-80 Hz频段的减振效果差;Ⅲ型轨道减振器扣件能较好地衰减钢轨和道床间各频段的振动传递;钢弹簧浮置板轨道对振动的衰减效果最好,但其对低频段振动衰减较高频段差。（2）比较不同测试断面的隧道壁振动加速度级,Ⅲ型轨道减振器扣件在工作频段内相对普通扣件的减振效果为10-15 dB;钢弹簧浮置板轨道在工作频段内相对普通扣件的减振效果为10-25 dB,且在20-50 Hz和80-200 Hz频段的减振效果明显优于Ⅲ型轨道减振器扣件。

To meet the environmental vibration requirements at multiple sensitive points,kinds of vibration reduction measures are adopted for Beijing Metro Line 5.For the sections of the under ground line,ordinary fastenings are installed in sections under general vibration-reduction requirements.Rail Vibration Absorber Fastening Type Ⅲ in sections under high vibration-reduction requirements and the steel spring floating slab track（SSFST） in sections under special vibration-reduction requirements.In order to evaluate the practical effect of the above vibration reduction products,in-situ Metro-induced vibration tests of the underground lines have been performed with the highly sensitive acceleration sensors.The vertical vibration acceleration levels of rails,track beds and tunnel walls at different measuring cross-sections are compared in the time domain and frequency domain.The results show as follows：（1）Ordinary fastenings reduce Vibration transmission between rail and track bed effectively except for in the 20~80 Hz band,Rail Vibration Absorber Fastening Type Ⅲ reduces Vibration transmission between rail and track bed in all frequency bands to good effect,and SSFST is the best in Vibration attenuation,its performance being better in high-frequency bands than in low-frequency bands;（2）comparing the vibration acceleration levels of tunnel walls at different measuring cross-sections,the vibration attentuation effect of Rail Vibration Absorber Fastening Type Ⅲ is better than the ordinary fastening by 10~15 dB in the working-frequency band,and the effect of SSFST is better than that of the ordinary fastening by 10~25 dB in the working-frequency band and is obviously better than that of Rail Vibration Absorber Fastening Type Ⅲ in the 20~50 Hz and 80~200 Hz bands.