Novel sensor-based solutions for offshore foundations health monitoring

该项目旨在研究一种新的海上基础健康监测战略，以降低深水(50米水深)的风险和成本。该项目的一个特别重点是监测地基冲刷和其他与海床移动有关的问题。冲刷是指由于水流冲刷物体周围的沉积物(如沙子或淤泥)，以往的研究表明，冲刷已成为导致近海工程结构破坏的关键因素之一。如果不加以控制，过度的冲刷可能会导致资产表现恶化，最终导致系统故障。因此，监测冲刷对确保持续安全作业至关重要。然而，随着我们进入更深的水域(由于仪器、后勤或劳动力原因)，现有的监测战略通常成本更高，部署起来也更困难。此外，现有的策略在细节上是有限的，通常只在一个位置测量冲刷深度。这不足以量化实际的冲刷风险，因为最近的研究表明，冲刷坑的形状在确定资产表现恶化时很重要。因此，需要可靠的监测工具来管理风险。一种前景看好的监测战略是使用水下航行器进行远程监测，它可以很容易地以较低的成本和风险部署在深水中。然而，现有的传感器在浑浊的水域中能见度较低，视野有限，不适合对冲刷条件进行详细的综合测绘。该项目将通过开发一种新的传感器来解决这一限制，该传感器可以比现有解决方案更详细地监测冲刷条件，并以更低的成本和风险进行监测。该传感器将能够扫描其周围环境，以生成冲刷坑的高分辨率三维(3D)模型。这与现有的冲刷监测策略不同，现有的冲刷监测策略通常只测量单个点的冲刷深度。将进行实验测试，以验证新传感器和所提出的水下机器人冲刷监测策略的可靠性。

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.