NEESR-SG: Physical modeling of 3D Tsunami Evolution Using a Landslide Tsunami Generator

海啸可以由地震冲击直接产生。然而，在一些地震事件中，海啸被观察到是由海底以巨大的海底滑坡的形式发生的大规模破坏引发的。根据国家地球物理数据中心和世界固体地球物理数据中心以及政府间海洋学委员会的资料，仅在太平洋，就发生了65起由海底滑坡引起的海啸事件，共造成14 661人死亡。我们最终的长期目标是对引发海啸的滑坡和随后的海啸产生、传播和上升的机制有一个基本的了解，这将有助于改进滑坡和海啸危害的评估和可能的减轻。不幸的是，来自真实世界观测的现场数据仅限于极少数情况，而这些数据中与海啸产生阶段有关的最重要部分几乎完全缺失。本研究的目标是利用一种新型的滑坡海啸发生器对三维海啸演变进行物理建模，以弥补这一数据的不足，该发电机将补充现有的NEES海啸设施。为了实现这一目标，在拟议的研究中将实现以下目标子集：目标1。模型相似度：控制模型相似度定义了拟议的滑坡海啸发生器的设计参数，将通过量纲分析确定。目标2。一种新型的滑坡海啸发生器：提出了一种新型的计算机控制的气动滑坡加速机制，将能够单独控制滑坡的动态参数，如滑坡位置、几何形状和加速度。目标3。滑坡参数：为了设计实验方案，我们建议从案例历史中确定海啸性滑坡的几何形状和速度。然而，为了涵盖所有可能的参数组合，我们正计划使用新的海啸性滑坡剪切带传播机制的分析和数值模型。目标4。实验方案：在拟进行的实验中，对水下滑坡运动特征和近场海啸的产生、传播和上升进行三维测量。此外，由此产生的滑坡沉积物将被绘制并记录其厚度。目标5。验证所提出的机制：将测量到的滑坡和海啸特征与现有的真实世界观测结果进行比较，为本研究中使用的物理、分析和数值模型提供验证。这将证明在发展对耦合滑坡和海啸机制的基本理解中使用这些模型是合理的，并使我们能够为未来的实验和理论研究提出建议。预期的学术价值：建议的研究将促进对滑坡引发的海啸的认识和理解。最具破坏性的自然灾害之一。提出的工作的独创性是基于其跨学科的性质，它结合了实验和理论流体，土壤和断裂力学方法。该项目是佐治亚理工学院三位教员的共同努力，他们结合了流体力学、物理建模和海啸灾害、土壤力学和岩土工程、岩石和断裂力学方面的专业知识。预期研究的更广泛影响：了解滑坡和海啸机制不仅对工程而且对人类活动具有广泛的影响。它将加强海啸和山体滑坡灾害的评估和减灾工作。本研究开发的新型滑坡发生器将在当前和未来的研究中补充现有的NEES海啸设施。该提案提供的资金将用于教育和支持两名研究生。这项研究的结果将纳入现有的本科和研究生水平的课程，并将由pi共同开发一门新的关于自然灾害的研究生课程。研究结果将通过在高影响力的专业期刊上发表的出版物和在国家和国际会议上发表的报告向广泛的科学和工程读者传播。K12的听众将通过流行的讲座和互联网帖子来强调土木工程专业在减轻自然灾害方面的重要作用。

Tsunamis can be generated directly by seismic impact. However, in some seismic events tsunamis have been observed to be triggered by the massive failure of the sea floor in the form of giant submarine landslides. According to the National Geophysical Data Center and World Data Center for Solid Earth Geophysics as well as Intergovernmental Oceanographic Commission, in the Pacific Ocean alone, 65 tsunami events attributed to submarine landslide caused a total number of 14,661 deaths. Our ultimate long-term goal is to develop a fundamental understanding of the mechanism of tsunamigenic landslides and subsequent tsunami generation, propagation, and run-up, which would allow for improved assessment and possible mitigation of the landslide and tsunami hazard. Unfortunately, the field data from real world observations are limited to very few cases, while the most important part of this data related to the tsunami generation stage is almost completely missing. The goal of the proposed research is to compensate for this lack of data by the physical modeling of 3-dimensional tsunami evolution using a novel landslide tsunami generator which will complement the existing NEES tsunami facilities. Towards this goal, the following subset of objectives will be achieved in the proposed research: Objective 1. Model Similitude: The governing model similitude, defining the design parameters for the proposed landslide tsunami generator, will be determined using dimensional analysis. Objective 2. A Novel Landslide Tsunami Generator: The proposed novel computer controlled pneumatic landslide acceleration mechanism, will enable individual control of the dynamic landslide parameters such as landslide location, geometry and acceleration. Objective 3. Landslide Parameters: To design of the experimental program we propose to determine the geometries and velocities of tsunamigenic landslides from the case histories. However, in order to cover the whole range of possible parameter combinations we are planning to use the novel analytical and numerical models of the shear-band propagation mechanisms of tsunamigenic landslides. Objective 4. Experimental Program: In the proposed experiments we shall measure the characteristics of the subaqueous landslide motion and the near-field tsunami generation, propagation and run-up in three dimensions. In addition the resulting landslide deposits will be mapped and their thickness recorded. Objective 5. Validation of the Proposed Mechanisms: The measured landslide and tsunami characteristics will be compared to the existing real world observations providing a validation for physical, analytical and numerical models used in this research. This will justify the use of these models in the development of fundamental understanding of the coupled landslide and tsunami mechanisms and allow us to develop recommendations for the future experimental and theoretical research. Expected Intellectual Merit of the Research: The proposed research will advance knowledge and understanding of landslide generated tsunamis . one of the most devastating natural hazards. Originality of the proposed work is based on its interdisciplinary nature, which combines experimental and theoretical Fluid, Soil and Fracture Mechanics approaches. The project is a joint effort between three Georgia Tech faculty members who combine expertise in fluid mechanics, physical modeling and tsunami hazards, soil mechanics and geotechnical engineering, rock and fracture mechanics. Expected Broader Impact of the Research: Understanding of landslide and tsunami mechanisms has broad implications not only to engineering but also to human endeavors. It will enhance both assessment and mitigation of tsunami and landslide hazards. The novel landslide generator developed in this research will complement existing NEES tsunami facilities both in the present and future studies. The funds provided from this proposal will be used to educate and support two graduate students. The results of this research will be incorporated into existing undergraduate and graduate level courses, and a new graduate course on Natural Hazards will be jointly developed by PIs. The results will be disseminated to a broad scientific and engineering audience through publications in high-impact professional journals and via presentations at national and international meetings. K12 audience will be reached by popular lectures and Internet postings emphasizing the important role of Civil Engineering profession in mitigation of natural hazards.