隧道衬砌质量地质雷达检测影响因素研究

摘要

针对目前隧道衬砌检测中存在的精度不高问题,采用理论分析和现场实际测试相结合的方法,分析了地质雷达衬砌检测精度的影响因素,研究表明:隧道衬砌检测准确性的关键在于衬砌介电参数ε的选取,衬砌混凝土强度和含水量在一定程度上决定了衬砌的介电常数和混凝土的龄期;利用线性回归确定了衬砌介电参数ε与混凝土水灰比、龄期以及强度的相关关系.在检测参数方面,表面波的拾取和数据处理理念对衬砌检测精度影响显著,采用不同频率的雷达天线时衬砌的检测精度不同.为提高衬砌检测精度在隧道拱顶、拱腰部位宜采用900 MHz天线,边墙部位宜采用400 MHz天线;在检测中需要根据衬砌混凝土的不同龄期采用不同的介电参数.%Aimed at the present problem that tunnel lining detection accuracy is not satisfactory,by adopting the combination of theoretical analyze and actual testing,analysis the factors that influence the accuracy of geological radar lining.The study indicates that the key of tunnel lining detection accuracy is the selection of dielectric parameter epsilon ε,and the strength of lining concrete and water content determines the dielectric constant and the concrete age in a certain extent;Linear regression is used to determine the relationship between the lining dielectric parameter epsilon ε,concrete water cement ratio,ages and the strength.In terms of detection parameters,the choosing of surface wave and data processing concept significantly effect on accuracy of lining,with different detection precision for different frequencies of the radar antenna in lining.To improve the accuracy of lining,USES 900 MHz antenna is appropriate for vault and arch waist,and sidewall part adopts USES 400 MHz antenna;According to the different ages of lining concrete,choose different dielectric parameters in testing.