Tunnel Lining Quality Evaluation And Model Test Research On Non-destructive Testing By Ground Penetrating Radar

As the mass construction of highway developing rapidly, the ground penetrating radar (GPR) has been widely applied to tunnel lining test. In this thesis, relying on the project of sampling inspection of construction quality of Jin-Wu-Huang (Chang) tunnel, we tested tunnel disease over 17 tunnels. From the test work, we got abundance useful information and accumulated some experience. However, we also met many problems in the process of field testing. For example, the testing precision of GPR and the judging basis for radar image etc. All these problems will affect testing precision of radar.The research of GPR technology involves the subjects of electromagnetism, material science and signal processing etc. The GPR technology is based on the electromagnetic theory, thus we must master propagating law of electromagnetic wave, which provides theoretical guide for analysis of experimental data. The reasonable setting of radar parameters are also very important, which can facilitate the collection of accurate radar data and help to skillfully master digital filtering technique and characteristics of wave and to improve data analysis and processing ability.The thesis gives the quality detecting evaluation of Jin-Wu-Huang (Chang) tunnel lining. The test contents include such items as the test of the thickness of sprayed concrete for every tunnel, the specification and distribution of steel arch centering, the primary support of suspended net steel bar, the steel bar distribution of secondary lining, the secondary lining thickness and the hollow area behind tunnel lining etc. According to these test contents, we analyze the image characteristics, and put forward some preventing measures. At last, after finishing non-destructive test of the project, we give the quality evaluation of tunnel lining. We hope that the achievement can help the engineers who engage in tunnel test.According to the water accumulation disease appeared in the cavities between lining and adjacent rock, we make some simulation experiments. In these experiments, a cavity between the lining and adjacent rock with different content of water is simulated. To be specific, we inject the water of the heights of 5cm, 10cm, 15cm, 20cm into the cavity successively, then use the America SIR-3000 GPR 900MHz antenna to test them, and get radar original images. After that, we use RANDAN6.5 to process radar original images and obtain radar oscillation profiles. Though the analysis on the radar oscillation profiles, we quantitatively analyze the heights of water, and compare them with practical corresponding heights of water. After analysis, some comments are as following: when the height of water is 5cm, the testing effect is not well, while, when the height is increased to 10cm, the test effect is significantly improved and better experiment results can be obtained;Finally, we conclude that the quantitative analysis of height of water is feasible.