Collaborative Research: Resilience of Geotechnical Infrastructure under a Changing Climate: Quantitative Assessment for Extreme Events

该奖项资助一个合作和跨学科的研究项目，重点是定量评估关键岩土基础设施的性能（即，天然和工程土结构）在当前和不断变化的气候下的极端气候和自然灾害。 虽然已经进行了一些大规模的研究，以评估气候变化的影响，有一个明显的差距，在我们的知识状态下的区域和结构规模的性能评估的岩土基础设施的各种表现形式的全球变化。 在这个项目中，我们专注于多种灾害，包括极端降水事件，海平面上升和极端温度的强度增加。 这项研究的结果预计将提高我们对我们的基础设施在最近的气候趋势下的弹性和可靠性的理解。 此外，这项研究将通过评估与气候变化相关的风险，加强对现有岩土基础设施的分析，以及未来岩土基础设施的设计和实施。在该项目方面，一些教育和外联工作（包括新的学习工具）将纳入调查人员教授的本科生和研究生课程。该项目还将为有兴趣从事科学和工程职业的学生提供基于项目的学习机会。该奖项将提供气候变化下岩土基础设施对极端事件的恢复力的定量评估。 该项目将解决以下研究问题：（1）气候变化的速率和变异性如何影响极端气候和自然灾害的重现时间间隔（2）土壤行为如何在气候调整极端条件下的热-水-力学（THM）过程中发生变化（3）极端气候和自然灾害如何影响岩土结构的短期和长期行为。为了正确解决这些问题，我们将量化气候变化对控制区域和结构性极端反应的两个因素的影响：供应（例如，土壤的剪切强度和压缩性）和需求（例如，由于极端气候和自然灾害而对结构施加的荷载）。 任务1将扩展非平稳极值分析（NEVA），以获得气候变化下极端事件的重现间隔。 采用NEVA将解决类似研究中的一个主要缺点，即忽视了变暖气候中极端事件的非平稳性。 任务2将包括使用NEVA输出来评估极端气候对多物理过程下土壤抗剪强度和压缩性的影响。 在任务3中，前两个任务的结果将被整合到一组数值和分析模型中，以模拟岩土结构的短期和长期行为。 工作的假设是，温度和土壤水分的变化在饱和土壤将支配的力学行为和土-结构相互作用的岩土基础设施。 研究目标是了解气候变化下极端事件对岩土基础设施的影响，并将这些影响纳入现有岩土基础设施的工程分析以及未来岩土基础设施的设计中。 为了实现这一目标，本项目的研究目标是：1）表征非等温条件下土壤的压缩性和抗剪强度，以及2）使用耦合THM数值和分析模型评估极端气候和自然灾害对关键岩土结构行为的影响。

This award funds a collaborative and interdisciplinary research project focused on quantitatively assessing the performance of critical geotechnical infrastructure (i.e., natural and engineered earth structures) to climatic extremes and natural hazards under current and changing climate. While several large-scale studies have been conducted to evaluate implications of climate change, there is a clear gap in the state of our knowledge on regional- and structural-scale performance assessment of geotechnical infrastructure under myriad manifestations of global change. In this project, we focus on multiple hazards including increased intensity of extreme precipitation events, sea-level rise, and temperature extremes. The outcome of this research is expected to enhance our understanding about the resilience and reliability of our infrastructure under recent climate trends. In addition, this research will enhance the current analysis of existing geotechnical infrastructure, as well as the design and implementation of future geotechnical infrastructure by assessing the risks associated with a changing climate. In connection with this project, a number of educational and outreach efforts (including new learning tools) will be integrated into undergraduate and graduate courses taught by the investigators. This project will also provide the opportunity of project-based learning for students interested in pursuing science and engineering careers.This award will provide a quantitative assessment of the resilience of geotechnical infrastructure to extreme events under a changing climate. The project will address the following research questions: (I) How does the rate and variability of a changing climate affect recurrence intervals of climatic extremes and natural hazards (2) How does soil behavior vary under thermo-hydro-mechanical (THM) processes imposed by climate-adjusted extremes (3) How do climate extremes and natural hazards affect the short-term and long-term behavior of geotechnical structures. To properly address these questions, we will quantify the impact of climate change on both factors governing regional and structural responses to extremes: supplies (e.g., shear strength and compressibility of soil) and demands (e.g., loadings imposed to the structure due to climate extremes and natural hazards) through three main Tasks. Task 1 will extend the Non-stationary Extreme Value Analysis (NEVA) to obtain recurrence intervals of extremes under climate change. Employing NEVA will address one of the main shortcomings in similar studies that ignore the non-stationary nature of extremes in a warming climate. Task 2 will include using NEVA outputs to assess the impacts of climate extremes on the shear strength and compressibility of soil under multi-physics processes. In Task 3, the results from the first two tasks will be integrated in a set of numerical and analytical models to simulate short-term and long-term behaviors of geotechnical structures. The working hypothesis is that variations in temperature and soil moisture in variably saturated soil will govern the mechanical behavior and soil-structure interaction in geotechnical infrastructure. The research goal is to understand the impacts of extreme events under a changing climate on geotechnical infrastructure, and incorporate these impacts into the engineering analysis of existing geotechnical infrastructure as well as the design of future geotechnical infrastructure. In pursuit of this goal, the research objectives of this project are to: 1) Characterize the compressibility and shear strength of soil under non-isothermal conditions, and 2) Evaluate the impacts of climate extremes and natural hazards on the behavior of critical geotechnical structures using coupled THM numerical and analytical models.