地铁运行过程中在钢轨上产生的振动以应力波的形式沿着钢轨-轨底垫片-钢轨轨枕-道床-隧道-土体路径传播。为了探究在传播路径中的应力波基础特性变化情况,本文在室内搭建了一段地铁隧道钢轨模型,采用激光多普勒测振仪对试验模型不同部位的应力波信号进行了测量研究,并通过扫描式测振仪获取到了钢轨不同表面上的应力波波场真实传播过程,最后采用有限元仿真软件LS-DYNA对应力波传播过程中的波场变化特征从图像角度进行了对比分析。研究结果表明:钢轨上由轮轨相互作用激励产生的应力波信号主要以25Hz~400Hz低频和1400Hz高频信号为主,而最终传播至土体内的应力波信号则主要以25Hz~200Hz的低频信号为主；通过与实测数据的对比,本文搭建的钢轨试验模型在动力性能方面同实际地铁隧道基本保持一致；信号数据分析结果和波场云图结果均表明:应力波的高频成分在从钢轨传播至混凝土轨枕阶段衰减最快,信号能量传递率最低；通过对比激光多普勒测振仪与计算机仿真的应力波波场结果,可以从图像角度验证计算机仿真方法的正确性；同时,复杂介质和模型中的波场研究可以由激光多普勒测振仪的结果替代计算机仿真结果。研究成果对于地铁轨道结构的安全设计与波场分析具有借鉴价值。

During the operation of a subway, vibrations generated on the steel rails propagate as stress waves along the rail-rail pad-steel rail sleeper-ballast-tunnel-soil path. In order to investigate the variations in the fundamental characteristics of stress waves along this propagation path, this study constructed an indoor model of a subway tunnel with steel rails. A Laser Doppler Vibrometer (LDV) was used to measure stress wave signals at different locations of the experimental model, and a scanning Laser Doppler Vibrometer (LDV) was employed to capture the real propagation process of stress waves on different surfaces of the steel rails. Finally, the LS-DYNA finite element simulation software was utilized to perform a comparative analysis of the changes in wave field characteristics during stress wave propagation from an image perspective. The research results indicate that the stress wave signals generated by the wheel-rail interaction on the steel rails are mainly characterized by low-frequency signals ranging from 25Hz to 400Hz and high-frequency signals at 1400Hz. On the other hand, the stress wave signals propagated into the soil primarily consist of low-frequency signals ranging from 25Hz to 200Hz. By comparing with the measured data, the steel rail experimental model constructed in this study exhibits a consistent dynamic performance with the actual subway tunnel. The analysis of the signal data and the wave field contour maps both indicate that the high-frequency components of the stress waves attenuate most rapidly during propagation from the steel rail to the concrete sleeper, exhibiting the lowest signal energy transfer rate. The comparison between the Laser Doppler Vibrometer (LDV) and computer simulation results of the stress wave field validates the accuracy of the computer simulation method from an image perspective. Additionally, the study suggests that the results obtained from the Laser Doppler Vibrometer (LDV) can serve as an alternative to computer simulation results in the investigation of wave fields in complex media and models. The research findings hold valuable implications for the safety design and wave field analysis of subway track structures.

基于人工智能的地下空间结构安全智能化感知与监控关键技术研究及示范项目21DZ1204400