Deformation and Failure Behavior of Soils under Erosion

侵蚀下土壤的变形和破坏行为

• 批准号: 0928433
• 负责人: Ching Chang
• 金额: $ 16.98万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928433&HistoricalAwards=false
• 关键词: Deformation; Failure; Behavior; Soils; under

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Soil erosion is the main cause of failure for dams and levees and can have disastrous consequences, such as the catastrophies in New Orleans in 2006 and in Iowa in 2008. According to the latest Report Card for America?s Infrastructure, issued in 2009 by the American Society of Civil Engineers, dams and levees are in the D minus range. Many dams and levees are structurally deficient and barely above failing. The risk of internal erosion in earth structures becomes a critical issue. The main goal of this research is to address the mechanics of deformation and instability caused by internal erosion. A stress-strain model will be developed that will (1) consider the micro-scale mechanism of pore collapse, and (2) account for the evolution of internal structure such as specific volume and gradation. T his stress strain law will be implemented into a finite element method capable of analyzing earth structure under erosion. This research work will be conducted in collaboration with Ecole Centrale de Nantes, where an experimental soil erosion research program is currently in progress. The collaborator will provide experimental results necessary for this research.The scientific significance of this research is twofold: (1) The investigation will lead to a new direction of damage mechanics, in which the damage is not caused by external load, but rather by a loss of part of the material constituents. (2) The micromechanics modeling method, in which the behavior is derived from postulated mechanisms, will provide insight into the underlying physical processes. The study will also bring the mathematical expressions of soil fabric (such as voids and particle size distribution) into the physics of constitutive models, which is of core importance to a constitutive theory for soil.The broader impacts will be as follows: (1) Integrate research and education by incorporating the research results and activities into graduate courses on sear strength and soil mechanics. (2) Broaden participation and enhance diversity by involving undergraduate students from the Northeast Alliance Program at the University of Massachusetts, an NSF funded program aimed at recruiting underrepresented minority students into doctoral study in science and engineering. (3) Enhance infrastructure for research and education by establishing international collaboration with the Civil Engineering Laboratory of Nantes.Saint-Nazaire. (4) Develop a defense against natural disasters such as landslides and floods through the enhancement of civil engineering infrastructure.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。土壤侵蚀是大坝和堤坝失败的主要原因，可能会产生灾难性的后果，例如2006年新奥尔良和2008年爱荷华州的灾难。 根据最新的美国报告卡？根据美国土木工程师学会2009年发布的《基础设施》，水坝和堤坝属于D-范围。 许多水坝和堤坝在结构上存在缺陷，几乎濒临崩溃。土结构内部侵蚀的风险成为一个关键问题。本研究的主要目标是解决内部侵蚀引起的变形和不稳定的力学。 将开发一个应力-应变模型，该模型将（1）考虑孔隙塌陷的微观机制，以及（2）解释内部结构的演变，如比容和级配。将该应力应变规律应用到有限元法中，可用于分析侵蚀条件下的土体结构。这项研究工作将与南特中央学校合作进行，该学校目前正在进行一项实验性土壤侵蚀研究计划。 本研究的科学意义有两个方面：（1）本研究将为损伤力学开辟一个新的方向，即损伤不是由外载荷引起的，而是由材料的部分成分损失引起的。(2)微观力学建模方法，其中的行为是来自假设的机制，将提供深入了解底层的物理过程。 本研究还将把土结构（如孔隙和颗粒尺寸分布）的数学表达式引入到对土的本构理论至关重要的本构模型的物理学中，其更广泛的影响将是：（1）将研究成果和活动纳入到研究生的剪切强度和土力学课程中，将研究与教育结合起来。(2)通过让来自马萨诸塞州大学东北联盟项目的本科生参与进来，扩大参与并增强多样性，这是一个由国家科学基金会资助的项目，旨在招募代表性不足的少数民族学生进入科学和工程博士研究。(3)通过与圣纳泽尔南特土木工程实验室建立国际合作，加强研究和教育基础设施。(4)通过加强土木工程基础设施，发展对山体滑坡和洪水等自然灾害的防御。