Segment hidden crack identification method based on matching pursuit and wavelet transformation

Abstract

The invention discloses a segment hidden crack identification method based on matching pursuit and wavelet transform, and a technology of combining orthogonal matching pursuit and wavelet transformation is adopted to process a shield tunnel lining hidden water-containing micro-crack geological radar detection signal, the influence of a strong impedance interface can be effectively weakened, and micro-weak reflection signals of a target detection object are enhanced, so that the purpose of accurately detecting and identifying the shield tunnel lining hidden quality defects is achieved. Firstly,according to the sparse representation theory, a surface strong reflection and abnormal strong reflection stripping method for layer and wavelet constraint matching pursuit is provided, and by combining a matching pursuit algorithm and a strong reflection forming mechanism, a sparse dictionary matched with the characteristics of the strong reflection signals is selected, and two-time matching decomposition is carried out on each signal, so that the micro-weak target reflected signals submerged in the strong reflection can be well displayed. Secondly, a wavelet basis function matched with thesignal and a proper wavelet transformation scale are selected, and the image profile is processed and enhanced again by adopting a continuous wavelet transform method, so that the hidden water-containing micro-crack signals are effectively highlighted.

Description

technical field [0001] The invention relates to the field of non-destructive testing of shield tunnel lining structures, in particular to a segment hidden crack identification method based on matching pursuit and wavelet transform. Background technique [0002] Shield method tunnel construction is more and more popular in my country's infrastructure construction because of its small impact on the surrounding environment, strong adaptability to complex strata and strata with poor geological and hydrological conditions, construction is not affected by wind and rain, and is safe and fast. At the same time, with the continuous advancement of alternative shield machine types and shield construction methods, as well as the improvement of the quality of shield equipment and the reduction of costs, the shield method has gradually become the mainstream construction method in underground railway construction. Shield tunnels are mainly composed of lining structures. Prefabricated lining...

AI Technical Summary

Problems solved by technology

However, affected by design factors, construction techniques, cyclic loads, and the operating environment, shield tunnels generally suffer from lining cracking and water leakage to varying degrees during the construction or service period.

Especially when there are hidden cracks in the lining structure, the consequences are more serious and difficult to deal with. Hidden cracks in the lining structure are characterized by concealment, imperceptibility and detection, which may lead to permanent quality defects in the project.

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