Information Extraction and Data Fusion for Nondestructive Evaluation of Concrete Bridge Decks

The objective of the dissertation is to improve and extend the application of impact echo (IE) and ground penetrating radar (GRP) methods in the field of concrete condition evaluation. At the beginning, an ensemble empirical mode decomposition (EEMD) approach is proposed to decompose the IE testing data into different spectral composition for defect signal extraction. The EEMD approach overcomes the challenge of extracting reflected P-wave from the IE signal that may contain strong surface wave. Then, to realize direct visualization of internal defects of concrete structures, an automated data fusion and visualization process is developed based on IE testing with source-receiver arrays. Both the simulation and experimental results demonstrate that the proposed method can effectively extract delamination regions from the IE data. In the end, the f-x variational mode decomposition (f-x VMD) method is adopted to remove the direct wave clutter of GPR Data from RC bridge decks, which are the main problem hindering the discrimination of the target of interest. The superiority and effectiveness of proposed methods are demonstrated in simulation, experiment, and field test environments over the average background subtraction method and F–K filter with dip relaxation method.Ph.D