Scour Monitoring and Failure Prediction for Safe and Resilient Transportation Infrastructures

流水对桥墩基础土质的侵蚀(即冲刷)是世界范围内桥梁破坏的主要原因。在美国，近21,000座桥梁是冲刷临界的，在1966至2005年间，有记录的桥梁故障中约有60%是由冲刷直接或间接造成的。该项目将通过整合实验、数值和理论研究以及教育努力来评估由冲刷引起的桥梁失效的风险。将进行的具体任务包括：设计冲刷传感系统；改进估计冲刷坑深度的理论；开发经过实验验证的准确的冲刷数值模型；以及系统测试和验证。在这个为期三年的项目中将完成的五项主要研究任务将使我们能够利用冲刷坑演变的直接传感器测量和数值模型更新来量化因冲刷而导致的桥梁故障的风险。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，并将对其进行优化，以便在具有挑战性的操作环境中使用。其次，传感器将用于测量喷流引起的冲刷坑演变，并将用于改善已建立的关系。然后，实施流固耦合模型，利用试验冲刷地形和桥梁动力响应数据进行修正，并通过严格的试验测试进行验证。冲刷网系统和数值模型也将通过使用位于台湾大学水利工程研究所的独特的冲刷监测试验台进行大规模测试来验证。最后，将利用蒙特卡罗模拟和概率方法评估不同水流和环境条件下桥梁因冲刷而失效的概率。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。研究成果将推进传感器技术、结构健康监测、水利工程和结构工程等领域的研究。能够监测冲刷，对冲刷进行及时建模和预测，并衡量冲刷对整个交通基础设施系统的影响，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先进的冲刷监测、湍流流动、冲刷、泥沙侵蚀和下部结构退化的计算模型更新的形式，以及试验和理论的结合以进行概率失效预测。

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.