Application of the Acousto-ultrasonics technique to bridge cables in their anchorages.

The objective of this research is to evaluate the state of health of civil engineering cable structures using the acousto-ultrasonics method. More specifically, the element to be examined is the cable in its non-accessible part inside the anchor base. Cables in anchor caps are sensitive areas subject to various types of damage, such as water infiltration, which causes corrosion inside the anchor, or fretting fatigue. Such degradation cannot currently be assessed using NDT techniques. A number of challenges need to be overcome, including the complex geometry of the anchors, which limits the installation of sensors, the diversity of damage that may be present, the sensitivity to the defects being sought and the reproducibility of the measurements. Once the acoustic signals have been acquired, data analysis is crucial, requiring the use of unsupervised or supervised techniques such as principal component analysis, or more advanced techniques such as decision tree forests. These approaches aim to determine the state of health of anchor caps from the analysis of acoustic signals, providing a reliable diagnostic for the assessment of these parts of engineering structures. This development could have major implications for the preventive maintenance and sustainability of cable infrastructures, by giving us a reliable and accurate method for assessing cable state.