CAREER: An Integrated Dissipative Modeling Framework for the Long-Term Assessment of Geohazards

这一学院早期职业发展(CALEAR)奖的重点是开发一种综合建模方法-将预测建模和模拟与最佳实验选择相结合-以及监测协议，以预测和减轻人为和自然地质灾害。这类地质灾害的例子包括山体滑坡、碎屑和泥石流、天坑、超压地下地带、障碍物和处置场、火山和地震。它们在人员伤亡和基础设施破坏方面往往是毁灭性的，而且在很大程度上仍然不可预测。这些地质灾害在很长的时间尺度上演化，长达数年或更长时间，延伸到超过数百米的领域，涉及易于内部微结构变化和转换的岩土材料的响应(如粘土、页岩、砂岩、泥岩、石灰岩)，并显示复杂的加载条件，在存在化学活性流体的情况下通常涉及热和/或超压。通过结合来自多个学科的技术，该项目朝着展示跨学科的、充满活力的方法如何将不同规模的运作过程联系起来的方向迈出了重要的一步。其目的是利用来自较低级别的材料信息，在实地建立一个耗散框架，以评估人为和自然地质灾害的长期潜力。这项研究得到了创新教育工具的补充--例如交互式3D模拟器--以及一个基于项目课程开发的推广计划，该计划针对广泛的受众，使岩土工程成为一门性别平等的学科。研究的具体目标是了解和量化主导材料在地质灾害中经常遇到的长期条件下的反应的物理因素。将通过开发和测试一个结合实验、理论和数值发展的综合框架来实现这一目标，在这个框架中，通过嵌套的多尺度数值方法，将来自小规模材料科学分析的信息吸收到一个计算辅助的本构框架中，并通过最先进的实验加以验证，然后将其提升到实地尺度。因此，这一项目的目标包括：(I)汇集材料科学、土壤和岩石力学、固体和流体力学、化学工程、热力学、计算力学以及应用数学和物理学等学科的概念，以确定和约束控制岩土材料长期响应的规律；(Ii)通过多尺度建模来量化耗散结构的能量收支，在该模型中通过不断监测微观结构和平均温度的测试来校准耗散结构；(Iii)根据微观结构数据和连续监测来预测选定的地质灾害的反应。该研究项目有能力提供关于岩土材料在长期、多物理加载中的响应的独特和变革性的知识，以及对地质灾害中运行的机械和物理过程的深刻见解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) award focuses on developing an integrated modeling approach –combining predictive modeling and simulations with optimal experimental selection— and monitoring protocols to predict and mitigate man-made and natural Geohazards. Examples of such Geohazards include landslides, debris and mudflows, sinkholes, over-pressurized underground zones, barriers and disposal sites, volcanoes, and earthquakes. They are often devastating in casualties and infrastructure damage, and remain largely unpredictable. These Geohazards evolve on very long time-scales, of years or more, extend to field dimensions exceeding hundreds of meters, involve the response of Geomaterials prone to internal microstructural changes and transformations (like clays, shales, sandstones, mudstones, limestones), and display complex loading conditions, often involving heat and/or overpressures in the presence of chemically active fluids. Through a combination of techniques from multiple disciplines, the project provides a major step towards demonstrating how interdisciplinary, energetic approaches may link processes operating at different scales. The aim is to develop a dissipative framework at the field scale using material information from the lower scales to assess the long-term potential of both man-made and natural Geohazards. The research is complemented by innovative educational tools –such as an interactive 3D simulator—and an outreach program based on project-based curriculum development targeting a broad audience to make geotechnical engineering a gender-equal discipline.The specific goal of the research is to understand and quantify the dominant physics governing the response of materials in the long-term conditions frequently encountered in Geohazards. This will be achieved by developing and testing an integrated framework combining experimental, theoretical and numerical developments, where information from material science analyses at the small scales is assimilated in a computationally-assisted constitutive framework through nested multi-scale numerical approaches, and validated through state-of-the-art experiments, before being upscaled to the field scale. Thus the objectives of this project include: (i) bringing together concepts from disciplines including material science, soil and rock mechanics, solid and fluid mechanics, chemical engineering, thermodynamics, computational mechanics, and applied mathematics and physics, in order to identify and constrain the laws governing the long-term response of geomaterials; (ii) quantifying the energy budget of dissipative structures through multi-scale modeling, calibrated via testing in which both the microstructure and the average temperature are continuously monitored; (iii) predicting the response of selected Geohazards from microstructural data and continuous monitoring. The research project has the capability of offering unique and transformative knowledge on the response of Geomaterials in long-term, multi-physical loading, as well as deep insights into the mechanical and physical processes operating in Geohazards.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.