NEESR: Tsunami Induced Coherent Structures and their Impact on our Coastal Infrastructure

NEESR：海啸引发的连贯结构及其对沿海基础设施的影响

• 批准号: 1135026
• 负责人: Diane Foster
• 金额: $ 127.5万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1135026&HistoricalAwards=false
• 关键词: NEESR; Tsunami; Induced; Coherent; Structures

The destruction from earthquake-induced tsunamis in the U.S. and other Pacific Rim countries can result in considerably more damage and deaths than the seismic ground motion. The goal of tsunami research is to save lives and reduce economic losses. To do this, we must develop sufficient scientific knowledge and appropriate engineering tools on which to base comprehensive tsunami mitigation plans and communicate this information effectively to decision makers, the emergency planning community and the public. The overarching theme of this effort is to formulate the complex processes affecting our coastal structures that are driven or affected by turbulent coherent structures (TCS). The role of wall bounded TCS in multiple forcing environments will be examined. Near the seabed, sediment pickup and transport can be significantly enhanced by TCS, leading to extreme scour and infrastructure failure. In the horizontal plane, TCS can appear as giant whirlpools and are commonly associated with extreme damage in ports and harbors. Extensive experiments will be performed at the Oregon State University (OSU), using the Large Wave Flume (LWF) to study the fine detail of TCS significance on nearbed processes, such as mobilization and transport of sediment, as well as the Tsunami Wave Basin (TWB) to characterize the complete hydrodynamic structure of a large, horizontal TCS generated by a port. The observations will be complimented with a wide-reaching numerical effort. To study the detailed TCS generation and its effects on sediment suspension due to transient long wave motion, we will use 3D turbulence resolving simulation models, with grid resolutions on the order of 1 mm. Fully coupled with the flow models will be Discrete Element Models for individual sediment particles, permitting grain-resolving simulation of tsunami-induced transport. Coupling the LWF and the TWB results with the fine resolution numerical tools will allow for predictions of bed mobilization, scour, and harbor wall forces for a generic tsunami problem, including the combined forcing of the mean "uniform" tsunami flow and the very localized, complex velocities due to TCS. The broader impacts of the proposed activities are to ultimately reduce the loss of life and property due to tsunamis through assessing population at risk needs to be aware of the associated risk and be prepared to respond in case of a tsunami warning. Here, we take a two-pronged approach to public education of the hazards possible during a tsunami event. First, a program targeting middle and high school students in coastal states will be closely connected to the experimental research proposed in the TWB. Students will formulate a harbor tsunami response plan, that will be implemented and tested in the TWB. Second, we identify several ways to enhance the transfer of our intellectual efforts to various stakeholders. Our knowledge transfer to engineering practitioners will take the place with 2-3 webinars regarding harbor design, sediment scour, and sediment liquefaction. These webinars will provide information regarding both existing design practices as well as new knowledge gained. The practitioners will be receiving professional development credit and the sessions will be recorded on the NEESHub for future use.

在美国和其他太平洋沿岸国家，地震引发的海啸造成的破坏可能比地震地面运动造成的破坏和死亡要多得多。 海啸研究的目标是拯救生命和减少经济损失。 为此，我们必须发展足够的科学知识和适当的工程工具，以此为基础制定全面的海啸减灾计划，并将这一信息有效地传达给决策者、应急规划界和公众。 这项工作的首要主题是制定复杂的过程，影响我们的沿海结构，驱动或影响湍流相干结构（TCS）。 在多重强迫环境中，壁约束TCS的作用将被检查。 在海底附近，TCS可显著增强沉积物的收集和运输，导致极端冲刷和基础设施故障。 在水平面上，TCS可以表现为巨大的浅水池，通常与港口和海港的极端破坏有关。 将在俄勒冈州州立大学（OSU）进行广泛的实验，使用大型波浪水槽（LWF）研究TCS对近床过程（如沉积物的移动和运输）的重要性的细节，以及海啸波盆地（TWB），以表征港口产生的大型水平TCS的完整水动力结构。 这些观测结果将得到广泛的数值研究的补充。 为了研究详细的TCS生成及其对沉积物悬浮的影响，由于瞬态长波运动，我们将使用三维湍流解析模拟模型，网格分辨率为1毫米的顺序。完全耦合的流动模型将是离散元模型的个别沉积物颗粒，允许颗粒解析模拟海啸引起的运输。 耦合的LWF和TWB的结果与精细分辨率的数值工具，将允许床动员，冲刷和港口的墙壁力量的预测一般的海啸问题，包括平均“均匀”海啸流和非常本地化的，复杂的速度，由于TCS的组合强迫。 拟议活动的更广泛影响是，通过评估面临风险的人口需要了解相关风险并准备在海啸警报发生时作出反应，最终减少海啸造成的生命和财产损失。 在这方面，我们采取双管齐下的方法，对海啸事件期间可能发生的危险进行公众教育。 首先，一项针对沿海各州初中和高中学生的计划将与TWB提出的实验研究密切相关。 学生将制定一个港口海啸应对计划，这将在TWB实施和测试。 第二，我们确定了几种方法，以加强我们的知识成果转移到各个利益相关者。 我们将通过2-3场关于港口设计、沉积物冲刷和沉积物液化的网络研讨会向工程从业人员传授知识。 这些网络研讨会将提供有关现有设计实践以及获得的新知识的信息。 从业者将获得专业发展学分，课程将记录在NEESHub上供将来使用。