基于VMD-HHT 冲击回波法的隧道衬砌检测技术研究  

Research on Tunnel Lining Void Detection Technology Based on ImprovedVMD-HHT Impact Echo Method

作　　者：孟露 汪旭 卢松[1] 肖洋 MENG Lu;WANG Xu;LU Song;XIAO Yang(China Railway Southwest Research Institute Co.Ltd,Chengdu,Sichuan 611731,China)

机构地区：[1]中铁西南科学研究院有限公司,成都611731

出　　处：《铁道工程学报》2023年第11期75-82,共8页Journal of Railway Engineering Society

基　　金：中国中铁股份有限公司科技开发计划项目(2021-重点-04)。

摘　　要：研究目的:针对常规冲击回波法在进行隧道衬砌脱空检测时容易出现多重峰值、虚假频率等问题,提出以模糊熵和相关系数为综合目标函数的遗传算法对原始信号进行最优化变分模态分解(VMD),然后基于希尔伯特-黄变换(HHT)计算信号的边际谱,并据此进行脱空检测分析,解决了傅里叶变换对非平稳冲击回波信号分析存在的固有缺陷,并基于仿真信号和隧道衬砌物理模型检测信号对数据处理方法进行了验证。研究结论:(1)以模糊熵和相关系数为综合目标函数的遗传算法有效实现了VMD分解参数的最优化,避免了人为设定参数所具有的偶然性;(2)VMD能够自适应地实现对冲击回波信号不同主频分量的有效分离,不存在模态混叠,因此能够有效滤除噪音信号,提高数据信噪比;(3)本文所提出的基于改进VMD-HHT的冲击回波法能够对衬砌厚度进行可靠检测,且检测结果中主频清晰明显,干扰远小于常用的傅里叶变换,不容易产生误判,有效提高了检测精度;(4)由于傅里叶变换及VMD-HHT处理方法的检测结果均存在一定的误差,因此要精确判断衬砌是否存在脱空,需结合隧道衬砌为密实情况的结果进行综合对比分析。Research purposes:Aiming at the problems of multiple peaks and false frequencies in tunnel lining void detection by conventional impact echo method,a genetic algorithm with fuzzy entropy and correlation coefficient as the comprehensive objective function is proposed to optimize the variational mode decomposition(VMD)of the original signal.The marginal spectrum of the signal is calculated based on Hilbert-Huang transform(HHT),and the void detection analysis is carried out accordingly.The inherent defects of the Fourier transform in the analysis of non-stationary impact echo signal are solved,and the data processing method is verified based on the simulation signal and the detection signal of tunnel lining physical model.Research conclusions:(1)The genetic algorithm with fuzzy entropy and correlation coefficient as the comprehensive objective function effectively realizes the decomposition parameters optimization of VMD,which avoids the contingency caused by artificially setting parameters.(2)VMD can adaptively realize components separation with different dominant frequency of the impact echo signal.Because there is no mode aliasing in the decomposition result,the noise signal can be effectively filtered to improve the data signal-to-noise ratio.(3)The impact echo method based on improved VMD-HHT proposed in this paper can reliably detect the lining thickness owing to the clear and obvious dominant frequency in the detection results.The interference of the improved VMD-HHT method is far less than that of the Fourier transform result,which is not easy to misjudge,and effectively improves the detection accuracy.(4)Since there are errors in the detection results of lining thickness both by the Fourier transform and VMD-HHT method,it is necessary to conduct a comprehensive comparison in combination with the results of dense tunnel lining to accurately determine whether the lining contains void or not.

关 键 词：冲击回波法 衬砌脱空检测 VMD-HHT 遗传算法 边际谱 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]