基于GprMax的隧道衬砌非接触式检测模拟研究

Simulation and research of non-contact detection of tunnel lining based on GprMax

在隧道工程中,用探地雷达检测衬砌质量是一种较为先进的手段,但是常规的雷达检测方法是贴壁检测,存在着检测效率低、安全隐患大的问题。因此,本文提出了非接触式检测的方法,利用基于时域有限差分法的GprMax软件结合Matlab编程对隧道中常见的钢筋检测、二衬厚度、空洞等病害做了的非接触式正演模拟。通过建立"空白"模型对雷达图像进行后处理,得到了与空气距离的关系式、在一定空气距离下雷达反射强度与电导率的关系式,非接触式检测的雷达病害图谱,对隧道非接触式检测的研究具有一定的参考价值。

Ground penetrating radar( GPR) is an advanced method to detect lining quality in tunnel engineering.However,conventional radar detection method is wall-to-wall detection,which has the problems of low detection efficiency and high security risks. Therefore,a non-contact detection method is proposed in this paper,and the GprMax software based on finite-difference time-domain method and MATLAB programming are used for non-contact forward simulation of common diseases of tunnels such as steel bar detection,thickness of secondary lining,cavity and so on. By establishing a"blank"model to post-process radar images,the relationship between radar reflection intensity and conductivity at a certain air distance is obtained,and the radar disease atlas of non-contact detection has a certain reference value for the research of non-contact detection of tunnels.