NEESR-CR: Impact Forces from Tsunami-Driven Debris

该奖项是NSF 09-524项目征集“小乔治·E·布朗地震工程模拟网络(NEES)研究(NEESR)”竞赛的结果，其中包括夏威夷大学(UH，牵头机构)、利哈伊大学(LU，子奖)和俄勒冈州立大学(OSU，子奖)。该项目将利用利哈伊大学和俄勒冈州立大学的NEES设备场地。该研究项目的目标是提高我们对海啸驱动的碎片对建筑物的冲击力的理解和预测能力。特别令人感兴趣的是航运集装箱，几乎无处不在，即使满载也会漂浮。目前尚不清楚这类碎片击中建筑物的力量，例如疏散庇护所和燃料储存罐等关键港口设施。我们将在NEES@OSU和NEES@LeHigh进行实验，以提高我们对重碎片低速撞击的理解，并开发和验证两个数值模型：可用于设计的简化模型和基于计算流体力学的更复杂的流固耦合模型。这个基于模拟的模型将允许我们探索简单模型中未包括的复杂参数，并考虑实验未涵盖的场景。在NEES@LeHigh设施的实验中，我们将在实验中量化全尺寸海运集装箱撞击结构元素时的非线性行为。这些结果将被用来校准我们的计算模型。实验和模型结果将被用来设计一个更简单的1：5比例的模型，模拟容器的行为，用于NEES@OSU海啸研究设施的第二系列测试。在这些测试中，海啸“海浪”将把模型碎片推向测试结构。这些测试将提供来自水驱动的碎片的实际数据，这些数据将用于验证在密歇根大学开发的数值模型。OSU测试还将揭示周围流体质量可能导致的放大。类似的测试也将对“木质”碎片进行，如原木和电线杆。智力价值：地震和海啸工程的一个关键目标是“社区复原力”，即一个社区承受事件而不造成灾难性破坏的能力。海啸淹没区建筑物面临的一个重大威胁是海啸流产生的碎片的冲击；这些力量的特征对于与垂直海啸疏散避难所有关的生命安全尤为重要。建筑法规的规定不能很好地处理典型的海啸造成的废墟，如原木、电线杆和钢制集装箱。最近关于柔性碎片撞击的研究表明，波浪在碎片中的传播决定了施加在被撞击结构上的力，而由于周围流体的影响，可能发生的力放大取决于波在两种介质中的传播。该项目将获得一组丰富的实验数据，以揭示低速、重碎屑对结构物的撞击行为。此外，还将建立数值模型，以增强我们对碎片冲击力的模拟能力。广泛影响：这项研究的结果将有助于提高社区对海啸的抵御能力。其结果有可能显著影响碎片撞击设计力的规格，这是海啸避难所、燃料和化学品储存罐以及港口和工业设施的一个特别重要的设计考虑因素，所有这些设施都可能不可避免地位于海啸淹没区。此外，结果将适用于飓风驱动的水上碎片，并在一定程度上适用于桥墩、码头和船闸的驳船和船舶碰撞。与目前用于设计力的模型相比，这些模型是一个重大改进。该项目将包括夏威夷原住民本科生的大量参与，为他们提供在夏威夷以及俄亥俄州立大学和利哈伊进行暑期研究的机会。参与这个项目，包括在美国本土的大学开展研究的潜力，将鼓励他们继续研究生学习，并使他们获得他们原本不知道或不相信他们可以获得的教育机会。该项目涉及与日本在海啸碎片危害方面的两名顶尖研究人员进行国际合作，一名在名古屋大学，一名在港口和机场研究所。该项目的数据将被存档，并通过NEES数据库向公众提供。该奖项是国家减少地震灾害计划(NEHRP)的一部分。

This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the University of Hawaii (UH, lead institution), Lehigh University (LU, subaward), and Oregon State University (OSU, subaward). This project will utilize the NEES equipment sites at Lehigh University and Oregon State University.The objective of this research project is to improve our understanding of, and predictive capabilities for, tsunami-driven debris impact forces on structures. Of special interest are shipping containers, which are virtually everywhere and which will float even when fully loaded. The forces from such debris hitting structures, for example evacuation shelters and critical port facilites such as fuel storage tanks, are currently not known. We will carry out experiments at NEES@OSU and NEES@Lehigh to improve our understanding of low speed impact of heavy debris and to develop and validate two numerical models: a simplified model that can be used for design, and a more complex fluid-structure interaction model based on computational fluid dynamics. This simulation-based model will allow us to explore complex parameters not included in the simple model and to consider scenarios not covered by experiments.For the experiments at the NEES@Lehigh facility, we will quantify experimentally the nonlinear behavior of full scale shipping containers as they slam into structural elements "in air". These results will be used to calibrate our computational models. The experimental and model results will be used to design a simpler, 1:5 scale model that mimics container behavior for a second series of tests at the NEES@OSU Tsunami Research Facility. In these tests, tsunami "waves" will drive the model debris against a test structure. These tests will provide actual data from water-driven debris, which will be used to validate numerical models developed at UH. The OSU tests will also shed light on the amplification that may result from the surrounding fluid mass. Similar tests will be conducted for "woody" debris, such as logs and telephone poles.Intellectual Merit: A key goal for earthquake and tsunami engineering is "community resilience", that is, the ability of a community to withstand an event without catastrophic damage. A significant threat to structures in the tsunami inundation zone is impact from debris driven by the tsunami flow; characterization of these forces is especially important to life-safety related to vertical tsunami evacuation shelters. Building code provisions are not well-developed to handle typical tsunami-driven debris, such as logs, telephone poles, and steel shipping containers. Recent work on impact of flexible debris has shown that the wave propagation in the debris governs the forces applied to the impacted structure and that force amplification that may occur as a result of the surrounding fluid depends on the wave propagation in the two media. This project will obtain a rich set of experimental data to reveal the behavior of low speed, heavy debris impact on structures. In addition, numerical models will be created to enhance our simulation capability of debris impact forces.Broader Impacts: The results of this study will contribute to improving community resilience to tsunamis. The results have the potential to impact significantly the specification of design forces for debris impact, which is an especially important design consideration for tsunami shelters, fuel and chemical storage tanks, and port and industrial facilities, all of which may unavoidably be located in tsunami inundation zones. In addition, the results will be applicable to hurricane-driven, water-borne debris, and to some extent to barge and ship collisions of bridge piers, docks, and navigation locks. The models are a significant improvement over those which are currently used for design forces. The project will include significant involvement of Native Hawaiian undergraduate students, providing them opportunities to conduct summer research in Hawaii and also at OSU and Lehigh. Participation in this project, including the potential to carry out research at universities on the US mainland, will encourage them to pursue graduate studies and expose them to educational opportunities that they would otherwise not be aware of or not believe are accessible to them. The project involves international collaboration with two leading researchers in Japan on tsunami-debris hazards, one at Nagoya University and one at the Port and Airport Research Institute. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).