Gpr Detection Research Of The Diseases And Hidden Danger In Hydraulic Tunnel Lining

Compared with other nondestructive testing methods, GPR detection is fas-ter, more efficient and stronger antijamming capability, etc, and the distinguishing ability of GPR can reach cm-level.In recent years,GPR nondestructive testing technology has got more and more extensive research and application in both highway tunnel and railway tunnel quality testing field,But the GPR is still not widely applied to hydraulic tunnel.As the use of GPR becomes wider and deeper, our technology still can hardly exactly explain the shape, the size and the form of the disease which exists in the tunnel lining. Therefore, it is important to carry out the inversion theory research on the probe, determine the size of tunnel lining and shape inside the cavity quantitatively; provide the basis for testing by explaining the maps.This thesis firstly summarizes the theory of GPR and how it can be applied to the project. And it also analyzes the way to explore by using GPR and how to set parameters. For example,"YeShanHe" hydropower station’s Draw Water Tunnel in HuBei province well expounds a latest popular radar processing software for business called "Reflexw". In turn, this software analyses and shows the data of the GPR in tunnel lining.It introduces the development and the application of FDTD. Take the Maxwell equations of ground penetrating radar transmission mechanism for example, the conductive medium of two-dimensional TM wave forward modeling and without considering the medium in the magnetic loss of UPML absorbing boundary conditions are derived in detail which was used the matching condition of no reflection matrix, the model area and absorbing boundary zone of discrete forward difference formula was derived. We use MATLAB to realize the program which is based on UPML absorbing boundary conditions’ two-dimensional TM wave GPR.This program was used to do the forward simulation about the round void, rectangle void and triangle void. And the successful simulation was applied to "YeShanHe" hydropower station’s Draw Water Tunnel in HuBei province. In turn, it proves that the program is right.