Protecting infrastructure against flow-entrained debris - a new approach

飓风和海啸引发的沿海洪水或内陆山洪等极端事件造成了大范围的破坏，夺去了数千人的生命，同时影响了沿途的社区。2011年的日本东北海啸和2005年的美国卡特里娜飓风就是这种毁灭性事件的例子。如今，预警和疏散措施在很大程度上依赖于准确预测特定地点特定危险的潜在影响。无法预测碎片冲击和荷载对结构的影响一直是水利工程中未解决的问题之一。当前研究计划的主要目标是研究碎片运动、碎片筑坝和碎片对结构的影响机制，并为制定新的可靠的设计标准做出贡献。本文提出的研究思路是实地调查的观察和发现的直接结果，也是对当前设计指南和标准中关于碎片运动和影响的规定的批评和缺乏明确性/有效性的直接结果。长期目标是将这项研究开发的新概念、方法和工具纳入碎片负荷的量化和设计需求参数中，这些参数可用于改进位于洪水易发地区的基础设施的设计指南。来自加拿大（渥太华大学，德国汉诺威海岸研究中心和日本早稻田大学）的其他赠款和独特实验设施的额外资金将用于支持该研究计划，预计申请人将在未来十年内继续进行该研究计划。该研究项目是世界上为数不多的研究项目之一，其结果将最终导致可靠的设计指南和工具的发展，工程师、沿海地区管理者和规划者将使用这些设计指南和工具来正确设计位于洪水易发地区的沿海和水利基础设施。预期影响该研究项目有望成为一个逐步改变的发展，它将通过结合极端流动中携带的碎片的概率行为，极大地提高预测极端水动力和结构上碎片载荷的工具和模型的准确性。突破目前实验水力学的极限，将极大地推动工程师设计关键基础设施的方式，从而在自然灾害发生时拯救生命和保护经济资产。申请人先前的Discovery基金的研究工作已被纳入新的ASCE7第6章抗海啸结构设计标准，预计这一拟议研究项目的结果将成为这些不断发展的标准的宝贵补充。最后，本研究将培养3名博士，2名硕士和3名本科学生，他们将获得水利和海岸工程方面非常理想的高级技能。

Extreme events such as hurricane- and tsunami-induced coastal inundation or inland flash floods have caused wide-spread destruction and claimed thousands of lives while impacting communities located in their path. The Tohoku Tsunami 2011 in Japan and Hurricane Katrina 2005 in the US are examples of such devastating events. Nowadays, warning and evacuation measures rely heavily on accurately forecasting site-specific hazard potential implications at a specific site. The inability to predict the effects of debris impacts and loading on structures remains one of the unsolved problems in hydraulic engineering. The main goals of the current research program are to investigate the mechanisms of debris motion, debris damming and debris impacts on structures and to contribute to the development of new and reliable design standards. Research ideas proposed herein are direct results of observations and findings stemming from field investigations as well as of the criticism and the lack of clarity/validation of the provisions of the current design guidelines and standards with respect to debris motion and impact. The long-term goal is to incorporate the new concepts, methods, and tools developed from this research into the quantification of debris loads and design demand parameters that can be used to improve design guidelines for infrastructure located in flood-prone areas. Additional funding from other grants and unique experimental facilities in Canada (Univ. of Ottawa, Hannover Coastal Research Center-Germany and Waseda Univ.-Japan) will be used to support this research program, which is anticipated to be pursued over the duration of the next decade by the applicant. The results of this research program, one of the very few in the world, will ultimately lead to the development of reliable design guidelines and tools that will be used by engineers and coastal zone managers and planners to properly design coastal and hydraulic infrastructure located in flood-prone areas. Expected Impact This research program is expected to be a step-changing development which will dramatically increase the accuracy of tools and models predicting extreme hydrodynamic and debris loading on structures by incorporating the probabilistic behavior of debris entrained in extreme flows. Pushing the current limits of experimental hydraulics presents great potential to significantly advance the way engineers design critical infrastructure to save lives and protect economic assets when natural hazards occur. The applicant's research work from the previous Discovery grant has been incorporated in the new ASCE7 Chapter 6 design standard for tsunami resistant structures - it is expected that the results of this proposed research program will become valuable additions to these continuously-evolving standards. Finally, this research will result in the training of 3 PhD, 2 MSc and 3 BEng students, who will acquire highly desired, advanced skills in hydraulic and coastal engineering.