Non-Destructive Testing Techniques for Tunnel Seepage Detection

This technical report discusses the application of non-destructive testing (NDT) techniques, specifically ground penetrating radar (GPR) and ultrasonic imaging, for detecting water seepage in new highway tunnels. The report outlines the challenges faced by traditional inspection methods regarding accuracy and efficiency in identifying seepage points. It details how GPR can quickly locate seepage areas by measuring the time delay and amplitude variations of electromagnetic waves, while ultrasonic imaging analyzes wave reflections to determine the exact location of seepage. The report includes a case study of a tunnel under construction that encountered water seepage, necessitating a large-scale inspection. It describes the process of using GPR for initial scans followed by ultrasonic testing for precise location identification. The results from both techniques are compared, demonstrating their effectiveness in ensuring the structural integrity of the tunnel. The report concludes with recommendations for data management and subsequent maintenance work based on the findings.