Scour Monitoring and Failure Prediction for Safe and Resilient Transportation Infrastructures

流水对桥墩基础土材料的侵蚀（即冲刷）是世界范围内桥梁破坏的主要原因。在美国，近21,000座桥梁处于冲刷临界状态，在1966年至2005年期间，大约60%的桥梁损坏是直接或间接由冲刷引起的。该项目将通过综合实验、数值、理论研究和教育工作来评估冲刷引起的桥梁破坏的风险。将进行的具体任务包括：设计冲刷传感系统；冲刷孔深度估算理论的改进开发经实验验证的精确数值冲刷模型；以及系统测试和验证。在这个为期三年的项目中，我们将完成五项主要的研究任务，这将使我们能够通过直接传感器测量冲刷孔的演变以及更新数值模型来量化冲刷引起的桥梁破坏的风险。首先，将设计一个“冲刷网”硬件/软件系统，该系统可以测量冲刷地形，并对其进行优化，以便在具有挑战性的操作环境中使用。其次，传感器将用于测量射流引起的冲刷孔演化，并将用于改善已建立的关系。然后，利用实验冲刷地形和桥梁动力响应数据实现流固耦合模型，并通过严格的实验测试进行验证。冲刷网系统和数值模型也将通过位于国立台湾大学水利技术研究所的一个独特的冲刷监测试验台进行大规模测试。最后，蒙特卡罗模拟和概率方法将用于评估各种流量和环境条件下桥梁冲刷破坏的概率。该项目将产生评估水上桥梁冲刷完整性的基本方法、技术和数值工具。研究结果将推动传感器技术、结构健康监测、水利工程和结构工程等领域的研究。监测冲刷、建立模型并及时预测其演变，以及衡量其对整个交通基础设施系统的影响的能力，对于实现能够适应全球气候变化的安全、有弹性的下一代城市至关重要。研究的更广泛影响将以推进冲刷监测，湍流流体流动，冲刷，沉积物侵蚀和子结构退化的计算模型更新以及概率失效预测的实验和理论集成的形式出现。

Erosion of earth material at bridge pier foundations by flowing water (i.e., scour) is a leading cause of bridge failures worldwide. In the U.S., nearly 21,000 bridges are scour critical, and approximately 60 percent of documented bridge failures have been directly or indirectly caused by scour during 1966 to 2005. This project will assess the risk of scour-induced bridge failures by integrating experimental, numerical, and theoretical research and educational efforts. Specific tasks that will be conducted include: designing a scour sensing system; improving theory on estimating scour hole depths; developing experimentally validated and accurate numerical scour models; and system testing and validation. Five major research tasks that will be accomplished during this three-year project will allow us to quantify the risk of scour-induced bridge failure using direct sensor measurements of scour hole evolution coupled with numerical model updating. First, a "scour net" hardware/software system that can measure scour topography and will optimize them for use in challenging operating environments will be designed. Second, the sensors will be used for measuring jet-induced scour hole evolution and will be used to improve established relationships. Then, fluid-structure models will be implemented, updated using experimental scour topography and bridge dynamic response data, and validated by rigorous experimental testing. The scour net system and numerical models will also be validated through large-scale testing using a unique scour monitoring test bed located in the Hydrotech Research Institute of National Taiwan University. Finally, Monte Carlo simulations and probabilistic methods will be used for assessing the probability of bridge failure due to scouring under various flow and environmental conditions.This project will result in fundamental methods, technologies, and numerical tools for evaluating the integrity of overwater bridges to scouring. The results will advance sensor technology, structural health monitoring, hydraulic engineering, and structural engineering fields of study. The ability to monitor scouring, model and predict their evolution in time, and measure its impact on entire transportation infrastructure systems will be critical for achieving safe, resilient, next-generation cities that can adapt to global climate changes. Broader impact of research will be in the form of advancing scour monitoring, computational model updating of turbulent fluid flow, scouring, sediment erosion, and substructure degradation, and the integration of experiment and theory for probabilistic failure prediction.