Wavelet base construction method for ground penetrating radar signal based on lifting scheme

Abstract

The invention discloses a wavelet base construction method for a ground penetrating radar signal based on a lifting scheme. A method for constructing a matched wavelet according to a biorthogonal wavelet theory and target signal waveform characteristics is provided for a problem of extraction of the characteristics of a hole detection signal at the back of a tunnel lining. The method is based on aperfect reconstruction filter condition and a lifting scheme wavelet, different lifting operators and dual lifting operators are acquired by carrying out lifting and dual lifting on an initial biorthogonal filter, and the actual characteristics of the ground penetrating radar signal is combined to construct a new biorthogonal wavelet base which not only meets the linear phase and the tight support but also has the advantages of being high in signal matching degree with the ground penetrating radar signal and the like. According to the wavelet base construction method for the ground penetrating radar signal based on the lifting scheme, the wavelet base is applied to quantitative analysis of hole defects of an indoor hole detection test, and compared with other types of wavelets, the wavelet constructed by the lifting scheme can more accurately identify the time and the position of a mutation point of the hole defect signal, and quantitative analysis of the position and the vertical dimension of the hole defect in the tunnel engineering can be realized more accurately, so that the reliability and accuracy of the ground penetrating radar on the defect detection are greatly improved.

Description

technical field [0001] The invention relates to the field of non-destructive detection of defects behind tunnel lining structures, in particular to a wavelet base construction method for ground penetrating radar signals based on a lifting format. Background technique [0002] During the construction and long-term operation of the tunnel, due to the change of the ground stress field, the failure of the initial support and the defects of the tunnel design and construction, various diseases and problems will occur in the lining structure of the tunnel. The cracking of the lining structure and the void behind the lining are two of the more serious The main problems, especially the harm caused by the void behind the lining, are more serious. [0003] The specific reasons for the voids behind the lining are as follows: [0004] ①During tunnel construction, the smooth surface blasting was not properly controlled, resulting in over-excavation, and the construction unit did not fill...

AI Technical Summary

Problems solved by technology

[0015] In order to solve the problem of accurate positioning and quantitative identification of cavity defects behind the tunnel lining structure, the present invention solves the problem through the following technical solutions:

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