Research On GSSI Ground-penetrating Radar’s Explanation And Treatment In The Detection Of Tunnel Lining

By the development of Chinese economy, our country increased investment in theconstruction of railway、highways constantly, so that the tunnel will be increased.According to some problems that exist in the operated tunnel, quality testing in thetunnel construction has become an important part of the engineering quality detectionin the assurance. Ground penetrating radar technology as a new, efficientnon-destructive testing technology has been widely used in tunnel detection.Ground-penetrating radar can collect data continuously, and be able to visualize theradar image. In practical application, as the influence of various noise, the collecteddata need special processing software to process.And when determine the tunnel liningdefects,due to differences of the inspectors ‘s experience, results which made bydifferent person will be certain differences. The paper briefly described some dataprocessing methods of ground-penetrating radar, such as FIR processing,deconvolution, Hilbert transform and so on. Through these methods, it is successfulto suppress the noise and extract the useful signal.Based on practice, the paper use GSSI ground-penetrating radar’s application inthe actual tunnel lining quality detection, on the basis of previous experience,explainwhat should be pay attention to on the tunnel lining quality inspection. Such as thelayout of measuring lines, adjusting of the ground-penetrating radar ‘s parameters inthe tunnel lining quality inspection and so on. Due to the various differences of thedielectric constant of the tunnel lining\surrounding rock, steel and other variousengineering medium, different targets on the radar images show the differentcharacteristics of the waveform characteristics. According to these characteristics, theuse of design material, qualitative and quantitative analysis to explain the de fects in thetunnel lining. According to the judgment of defects appeared on the actual tunneltesting, combined with the field to break the certificate of inspection, we made a detailed analysis of defects which exist in the tunnel lining.The paper mainly study thejudgment of lacks such as steel arch, steel mesh, empty, not dense, and the thickness.According to the data processing steps in the actual project,the paper given theprocesses of the general data processing and the method of deficiency judgment.Studies have shown that in the tunnel lining quality inspection, the dielectricconstant ‘s calibration has an important influence on the subsequent data processingand reducing determine error after data processing. In practical engineering detection,error is inevitable, how to reduce the error is the issue that tunnel testing personmust consider. This article summarizes some of the causes of errors and methods forreducing errors. Through the application of these methods in practice, the accuracy andreliability of test results has been greatly improved.