盾构隧道内减振道床评价隧道壁测点位置研究

Measurement Positions of Shield Tunnel for Vibration‑Reducing Evaluation of Floating Slab Tracks

隧道内减振道床的在线测试现行方法不区分隧道的结构形式,且未考虑盾构隧道纵缝在振动传播过程中的影响。针对该问题,结合现场测试和数值模拟,分析盾构隧道纵缝在振动传播过程中的影响。结果表明:振动波在单一管片会随着离振源距离的增加而产生一定程度的衰减;盾构隧道纵缝对振动波有明显的削弱作用,振动波经过纵缝后振动加速度时程最大幅值可下降50%以上;无论哪种拼装角度,在同一振源激励下,盾构隧道被纵缝影响的一侧和未被纵缝影响一侧的振动加速度幅值和频率分布均存在显著差异;即使都位于未被纵缝影响的一侧,不同错缝拼装角度也会造成该侧测点动力响应幅值的不同。因此,在盾构隧道内进行振动测试时,应考虑纵缝位置及管片拼装角度的影响。

The method for online testing of the vibration isolation track in tunnels does not differentiate among various tunnel structural forms and overlooks the influence of longitudinal joints in shield tunnels during vibration propagation.To address this issue,this study combines field testing and numerical simulation to analyze the im‑pact of longitudinal joints in shield tunnels during vibration propagation.The research results show that the vibration wave of a single segment has a certain degree of attenuation with the increase of the distance from the vibration source,but the attenuation is not obvious;the longitudinal joints of the shield tunnel have a significant weakening effect on the vibration wave,and the maximum amplitude of the vibration acceleration can be reduced by more than 50%after passing through the longitudinal joints;no matter what the assembly angle is,there are significant differences in the amplitude and frequency distributions of vibration acceleration on the side affected by the longitudinal joints and the side unaffected by the longitudinal joints,even if they are located on the side unaffected by longitudinal joints.Regardless of the assembly angle,there are significant differences in the amplitude and frequency distribution of vibration acceleration between the side of the shield tunnel affected by the longitudinal joint and the side not affected by the longitudinal joint.Therefore,when conducting vibration testing in shield tunnels,the influence of longitudinal joint positions and segment assembly angles should be considered.