摘要
盾构法进行隧道施工时,浆液注入管片壁后形成注浆层是预防地质灾害的有效手段,然而壁后注浆质量难以直观地监测和控制.为此,利用全尺寸管片环形试验平台,开展了不同地质雷达天线频率、收发形式下壁后注浆填充的缺陷测试.研究结果表明,天线为900 MHz且布置方向与测线方向平行时测试效果最佳,同时含水的缺陷更容易被探测到.此外,提出了一种基于时空中值滤波的信号处理方法,针对管片壁后检测的地质雷达信号,达到剔除多次反射、提取壁后注浆缺陷体信号以及提高信噪比的目的.其中,沿时间轴的中值滤波方法能够适用于多次波反射强烈且规律性较强的信号,沿空间轴的中值滤波能够适用于各道信号对齐好,一致性较好的信号,两种方法能够相互补充、结合使用.在数值试验、管片模型测试数据以及施工现场实测数据中,成功实践了该滤波方法.该方法具有较好的稳定性、适用性,能够有效地压制信号中的多次反射波从而提取壁后注浆缺陷的有效信号.
In shield tunnel construction,injecting grout into the segment wall and surrounding rock is an effective measure to prevent geological disasters.However,controlling the quality of the grouting body is challenging.Ground penetrating radar(GPR)is used as a non-destructive testing method to detect defects behind the tunnel shield segments.In this study,a full-scale segment model test platform is used to verify test results obtained using several antenna frequencies and transceiver configurations under specific conditions and with various defect fillings.It is concluded that the 900 MHz antenna yields the best results when defects are filled with water.A signal processing method based on time and space median filtering is proposed to eliminate multiple reflections and extract the signal of grouting defects behind the tunnel shield segment.Median filtering along the time axis can be applied to signals with strong multiple reflections and regularity,while filtering along the space axis can be applied to signals with better alignment and consistency.These filtering methods have been successfully validated through numerical experiments,model tests,and field data.The results demonstrate that the combined methods are stable and applicable,effectively suppressing multiple reflected waves and extracting the effective signal of grouting defects behind the tunnel shield segment.
作者
徐国平
叶剑
王登一
黎超尘
刘鎏
彭铭
杨沛权
XU Guoping;YE Jian;WANG Dengyi;LI Chaochen;LIU Liu;PENG Ming;YANG Peiquan(CCCC Foshan Investment&Development Co.Ltd.,Foshan 528000,Guangdong China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Ministry of Education Key Laboratory of Geotechnical and Underground Engineering,Tongji University,Shanghai 200092,China;Guangdong Construction Engineering Quality and Safety Inspection Station Co.Ltd.,Guangzhou 510599,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)
出处
《河南科学》
2024年第6期804-815,共12页
Henan Science
基金
国家自然科学基金(41731283,41877234,42071010,42061160480)
中央高校基础研究基金(22120180538)。
关键词
隧道施工
盾构法
地质雷达
信号处理
无损检测
中值滤波
tunnel construction
shield method
GPR
signal process
non-destructive testing
median filtering
