地铁运行激励土体应力波基础特性研究  

Subway-induced soil stress wave fundamental characteristics research

作　　者：孔庆钊 桑笑晗 李杨 杨霞 朱福钢 韩磊 KONG QingZhao;SANG XiaoHan;LI Yang;YANG Xia;ZHU FuGang;HAN Lei(College of Civil Engineering,Tongji University,Shanghai 200092,China;Zhejiang Sunny Innovation Optical Intelligence Technology Co.,Ltd.,Yuyao 315400,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]浙江舜创智能光学科技有限公司,余姚315400

出　　处：《地球物理学进展》2024年第6期2432-2451,共20页Progress in Geophysics

基　　金：上海市科技委员会资助项目“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)资助。

摘　　要：城市地铁运行过程中产生的振动主要以应力波的形式向周围土体传播,为了深入研究并充分利用地铁振动产生的土体应力波对隧道周围地质情况开展探测,本文首先针对地铁激励产生的应力波在土体中的传播特性开展研究,以揭示其基础特性变化规律.采用激振器激励混凝土板的方式模拟地铁振动,并借助激光多普勒测振仪从不同角度采集土体应力波信号数据进行分析.研究结果表明:随着与振源距离的增加,土体应力波信号能量呈现出指数衰减趋势,且激振频率越高,衰减越快;与应力波传播方向垂直的方向上,随着测点与中心点间距离的增大,信号能量呈现出正态分布的特点;采用AIC法提取应力波信号的初至时间并计算波速,发现应力波速随着激励频率的增大而增大,表明土体内传播的应力波信号具有频散特性;随着与振源距离的增加,土体应力波信号主频范围呈现出向低频频带转移的规律,而垂直于信号传播方向的各测点信号主频范围则基本一致;最终稳定传播至地面的应力波主要以50 Hz的低频信号为主,该信号可用于最小尺度不低于0.6 m的土体内部异常体的探测;采用激光多普勒测振仪扫描获取土体表面应力波波场图,结果表明,贴近土体上表面的波场能量较为集中,扫描波场图实现了应力波在真实土体中传播状态的可视化,所得结果可用于计算机仿真结果的验证.本研究成果对于进一步探讨和利用地铁振动产生的土体应力波进行地质探测具有重要参考价值.This study focuses on the propagation of vibrations generated during the operation of urban subway systems in the form of stress waves through the surrounding soil. The aim is to investigate and utilize the soil stress waves generated by subway vibrations for geological exploration around tunnels. The research begins by studying the propagation characteristics of stress waves generated by subway excitations in the soil to reveal their fundamental variations. Concrete slabs are excited using a shaker to simulate subway vibrations, and soil stress wave signal data are collected from different angles using a Laser Doppler Vibrometer(LDV) for analysis. The research findings indicate that the energy of soil stress wave signals exponentially attenuates with increasing distance from the vibration source, and higher excitation frequencies result in faster attenuation. In the direction perpendicular to the propagation of stress waves, the energy of the signals exhibits a characteristic normal distribution as the distance between measurement points and the central point increases. The arrival time of stress wave signals is extracted using the Akaike Information Criterion (AIC) method, and the wave velocity is calculated. It is observed that the stress wave velocity increases with higher excitation frequencies, indicating the dispersive nature of stress wave propagation in the soil. As the distance from the vibration source increases, the main frequency range of soil stress wave signals shifts towards lower frequencies, while the main frequency range of signals in the direction perpendicular to the signal propagation remains relatively consistent. The dominant stress waves that stably propagate to the ground are mainly low-frequency signals at 50 Hz, which can be used for detecting anomalies within the soil with a minimum scale of 0.6 m. Scanning of stress wave field maps on the surface of the soil using a LDV demonstrates that the energy of the wave field is concentrated near the surface of the soil. The scanned wave field

关 键 词：地铁振动 土体应力波 多普勒测振仪 地质探测 赤池信息量准则(AIC) 

分 类 号：P631[天文地球—地质矿产勘探]