混凝土龄期对地质雷达信号特征的影响分析  

Influence of Concrete Age on GPR Test Results

作　　者：赵才 程忠 杨晓坤 张军[2] 张雷 张向文 Zhao Cai;Cheng Zhong;Yang Xiaokun;Zhang Jun;Zhang Lei;Zhang Xiangwen(Guangxin Testing and Certification Group Co.,Ltd.,Jinan Shandong 250002,China;Highway Maintenance Equipment National Engineering Laboratory,Chang’an University,Xi’an,Shanxi 710064,China)

机构地区：[1]广信检测认证集团有限公司,山东济南250002 [2]长安大学公路养护装备国家工程实验室,陕西西安710064

出　　处：《工程地球物理学报》2024年第4期700-712,共13页Chinese Journal of Engineering Geophysics

基　　金：广西交通运输行业重点科技项目(编号:19-09);陕西省自然科学基础研究计划(编号:2022JM-249)。

摘　　要：为解决新建隧道的含水率高,导致地质雷达(Ground Penetrating Radar,GPR)信号能量衰减严重,无法检测到脱空病害区域的问题。首先,通过正演实验模拟不同含水率条件下的地质雷达信号响应。随后,在实际工程中设置验证实验,采集地质雷达数据并分析其特征。特别关注钢筋网对信号的影响,并根据实验结果提出针对性的解决方案。最后,比较不同龄期条件下地质雷达图谱特征,确定最佳检测时机。实验结果显示,高含水率和钢筋网的存在显著影响地质雷达信号特征。在低含水率条件下,地质雷达图谱特征更为明显,有利于脱空病害的准确检测。新建隧道素混凝土结构建议龄期120 d、钢筋混凝土结构龄期180 d后开展无损检测试验。本研究通过深入探究地质雷达信号在不同含水率条件下的响应特征,确定了最佳的检测时机和方法。针对高含水率和钢筋网对信号的干扰,提出了相应的解决方案,为隧道脱空病害的无损检测提供了重要技术支持。To address the issue that high water content in newly constructed tunnels causes significant attenuation of ground penetrating radar(GPR)signals,rendering them unable to detect voiding areas,this study took the following steps:firstly,forward modeling experiments were conducted to simulate GPR signal responses under different water content conditions.Then validation experiments were set up in actual engineering scenarios to collect GPR data and analyze their characteristics.Special attention was paid to the influence of reinforcement bars(rebars)on the signal,and targeted solutions were proposed based on the experimental results.Finally,GPR data features under different aging conditions were compared to determine the optimal detection timing.The experimental results show that high water content and the presence of rebars significantly affect the characteristics of GPR signals.Under low water content conditions,GPR data features are more pronounced,facilitating accurate detection of voiding defects.For newly constructed tunnels with plain concrete structures,it is recommended to conduct non-destructive tests at the age of 120 days,while for reinforced concrete structures,testing should be carried out after 180 days.This study delves into the response characteristics of GPR signals under different water content conditions and identified the optimal detection timing and methods.Targeted solutions are proposed to address the interference caused by high water content and rebars,providing crucial technical support for non-destructive detection of voiding defects in tunnels.

关 键 词：隧道 地质雷达 混凝土龄期 

分 类 号：P631.3[天文地球—地质矿产勘探]