Defect Detection And Stability Analysis For Lining Structure Of Hydraulic Tunnel

As the tunnel engineering is a hidden project, it is difficult to achieve a perfect effect for support system on one-time. So there have three principles which is must to be strengthening during in the construction process,"timely detection, quickly found, and immediate repair" This paper was carried out under the above principles, and relying on the actual engineering’s requirments for quality testing services.Thesis has two main line, one of them is lining defect detection, and another is about of analysis of the stability of the lining. The former is an important prerequisite for the latter, while the latter is an important basis for the former practice, and both complement each other, the main content and results are as follows:(1)Study on the mechanism of electromagnetic theory and electromagnetic wave propagation in the medium, combined with SIR-3000type of GPR, introduces several criteria about how to select detection parameter. At the same time, also introduces the analysis and processing of data must be carried out in terms of a few basic premise.(2)Based on FDTD method, forward modeling is conducted on the propagation of electromagnetic waves. Firstly, to investigate the characteristics of electromagnetic wave propagation in a single defect by simulating several simple defect geoelectric model (lining thickness, lining void, water-filled voids, etc.). Secondly, comparative analysis of characteristics of electromagnetic waves by considering the medium diversity of defect and the diversity of defect shape. Finally, based on the form of a circular defect, study the propagation of electromagnetic waves by considering of the defect size and distribution. In conclusion, the results reveal the characteristics of electromagnetic wave propagation in a complex defects. On the other hand, the results could provide the basis for the GPR data interpretation.(3)Combined with the engineering characteristics, detection scheme and the working process were designed in lining defect. Applied the GPR technology into quality detection of Dong-song hydraulic tunnel, and achieved good results, realize the construction of quality evaluation of tunnel lining structure.(4) From two perspectives and four states to study the response characteristics of lining internal forces. Then read lining sectional internal force by writing fish language, and used these data to evaluation the security of the lining accordance with the "design code for hydraulic concrete structures". By considering and systematic analysizing the relationship between the security of the lining and the defects, then achieved stability evaluation of lining structure. These evaluations enrich the research in this area.