基于小波分析提取大跨径公路桥梁运营期GPS变形监测中的动态特性  

Extraction of Dynamic Characteristics in GPS Deformation Monitoring of Large-span Highway Bridge during Operation Period on the Basis of Wavelet Analysis

作　　者：颜潮勇 Yan Chaoyong(Fujian Surveying and Mapping Institute,Fuzhou 350003,China)

机构地区：[1]福建省测绘院

出　　处：《甘肃科学学报》2019年第3期12-18,67,共8页Journal of Gansu Sciences

摘　　要：针对运营期大跨径公路桥梁GPS动态监测数据受观测环境污染导致无法准确提取桥梁动态特性的问题,研究了利用小波分析技术从GPS观测数据中提取大跨径桥梁动态特性时4种常用小波阈值的选取准则,提出了基于分层、分段的处理方法处理桥梁GPS动态监测数据在不同阶段产生的不同大小振幅和噪声,最后将小波包技术应用在桥梁GPS动态监测数据高频阶段有用信号的提取。以苏通长江公路大桥作为研究对象进行试验,分析显示4种小波阈值中固定阈值存在过度去噪的现象,而自适应阈值在去噪的同时可以保存桥梁GPS监测数据丰富的实际特征,采用分层、分段的方法对桥梁GPS动态监测数据进行处理,结果表明该方法既可得到光滑的去噪结果,又能够最大程度地保留桥梁信号的特征,使提取的大跨径桥梁变形信息更为丰富。对比分析小波包法与小波法的去噪结果,表明基于小波包法在对桥梁GPS动态监测数据去噪的同时能够保留桥梁高频信号中更多的有用动态特性。Targeted at the issue that the GPS dynamic monitoring data of large-span highway bridge is affected by the environment pollution and the failure in accurately extracting the bridge dynamic characteristics during the bridge operation period,the articles analyzes the selection rules of four common wavelet thresholds in extracting large-span bridge dynamic characteristics from GPS monitoring data by wavelet analysis technology,puts forward the application of layered and sectional processing of GPS dynamic monitoring data on the amplitude and noise of different grades generated in different stages,and the application of wavelet package technology on the extraction of useful signals in the high frequency phase of bridge GPS dynamic monitoring data.The result of experiment with Su Tong Yangtze River Highway Bridge as subject indicates that the excessive denoising exits in the fixed threshold of four wavelet thresholds and the self-adaptive threshold is capable of denoising and storage of the rich actual characteristics of bridge GPS monitoring data;the layered and sectional processing of GPS dynamic monitoring data may result in smooth denoising result and furthest retain the characteristics of bridge signal to enrich the extracted deformation information of large-span bridge;the wavelet package method may denoise the GPS dynamic monitoring data and retain more useful dynamic characteristics of high-frequency bridge signals after compare and analysis of the denoising results of wavelet package method and wavelet method.

关 键 词：大跨径桥梁 变形监测 动态特性 GPS观测数据 小波分析 小波阈值去噪 分层分段去噪 小波包分析 

分 类 号：P227[天文地球—大地测量学与测量工程]