Inspection method for high pressure and rich water geological tunnel lining based on GPR technology

When traditional tunnel lining detection methods are used in high-pressure and water rich geological conditions, when the lining is soaked in groundwater, noise appears in the imaging, which affects the crack detection results. Therefore, an efficient detection method for high-pressure and water rich geological tunnel lining based on Ground Penetrating Radar (GPR) technology was proposed. Tunnel lining cavity simulation based on GPR technology was simulated, the data generated by forward simulation was analyzed. Maxwell's discrete equation form was used and time-domain finite difference processing for GPR signal was carried out. Appropriate wavelet basis function was selected and evaluation indicators were obtained to achieve wavelet denoising of detection signal, which could effectively improve the accuracy of subsequent radar detection data analysis results. Lining crack types was divided and pixel distance calculation was used to achieve crack size detection. The application test results of the method showed that the designed lining efficient detection method and traditional detection method could accurately obtain crack types. For size detection results, the dispersion degree of the design method's results was lower than that of traditional methods, indicating that it was closer to the actual value and verifying the effectiveness of the method.