Novel sensor-based solutions for offshore foundations health monitoring

The project aims to research a new strategy for offshore foundations health monitoring that reduces risks and costs in deep waters (> 50m water depth). One particular focus of this project is on monitoring foundation scour and other seabed movement-related issues. Scour here refers to the removal of sediment (such as sand or silt) from around an object due to the flow of water and previous studies have shown that scour has become one of the key factors causing structural failures in offshore engineering. If left unchecked, excessive scouring may lead to asset performance deterioration and eventually, system failure. Monitoring scour is therefore of paramount importance to ensure continued safe operation. However, existing monitoring strategies are usually more costly and difficult to deploy as we move into deeper waters (either due to instrumentation, logistical or labour reasons). Furthermore, existing strategies are limited in details, typically measuring the scour depth at only a single location. This is inadequate for quantifying the actual scour risk as recent studies have shown that the shape of the scour holes matter when determining the asset performance deterioration. There is thus a need for reliable monitoring tools to manage the risk.
One promising monitoring strategy is remote monitoring using underwater vehicles, which can be readily deployed at lower costs and risks in deep waters. However, existing sensors have poor visibility in turbid waters and limited field of view (FOV), making them unsuitable for detailed comprehensive mapping of the scour conditions. This project will address this limitation by developing a new sensor that can monitor the scour conditions with much greater details and at lower costs and risks than existing solutions. The sensor will be able to scan its neighbouring surroundings to generate a high-resolution, three-dimensional (3D) model of the scour hole. This contrasts with existing scour monitoring strategies, where typically only measure the scour depth at a single point. Experimental tests will be carried out to validate the reliability of the new sensor and the proposed scour monitoring strategy using underwater vehicles.