Towards an Integrated Computational-Experimental Laboratory Testing Framework for Soil Behavior Characterization and Modeling

建立土壤行为表征和建模的综合计算实验实验室测试框架

• 批准号: 0856322
• 负责人: Youssef Hashash
• 金额: $ 38.1万
• 依托单位: University of Illinois at Urbana-Champaign
• 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: 2009-08-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0856322&HistoricalAwards=false
• 关键词: Towards; Integrated; Computational; Experimental; Laboratory

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The construction of any infrastructure on or within the ground will subject the surrounding soils to complex loading modes. In order to understand the short and long term behavior of an infrastructure element such as a building or a tunnel it is therefore essential to characterize the response of the surrounding soil. A soil material model that correctly captures soil behavior under general loading modes is requisite to solving such complex engineering problem known as a boundary value geotechnical engineering problems. Available laboratory tests are assumed to represent a single element and stress-strain path and do not cover the full range of loading paths experienced in a boundary value problem and is often insufficient to validate material model performance under general loading conditions.This research project will develop an integrated computational-experimental laboratory testing framework. Within this framework a laboratory test will be treated as a boundary value problem instead of a single element test. The test is coupled with an evolutionary inverse analysis approach that will allow for the extraction of multitudes of stress-strain paths generated within this boundary value problem. A soil-specific material constitutive model can be generated from this information. The test device is a modification of the widely used triaxial cell. The device includes lateral restraints in addition to frictional caps to induce non-uniform stress-strain states within the soil specimen. The device will be coupled with imaging techniques to capture the 3-D deformed shape of the specimen during loading. The novel inverse analysis algorithm, SelfSim, uses an evolutionary material constitutive model to extract the diverse stress-strain states from measured boundary loads and deformations. The constitutive model can be directly used within a numerical analysis (e.g. finite element method) of a geotechnical problem. The proposed research will open up new and exciting doors for fast, practical and more comprehensive soil behavior characterization. The proposed framework has the potential to transform material testing and characterization beyond geotechnical engineering. The project will support graduate and undergraduate researchers and will provide training to future engineers.

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。地基上或地基内任何基础设施的建设都会使周围土体承受复杂的荷载模式。因此，为了了解建筑物或隧道等基础设施要素的短期和长期行为，有必要描述周围土壤的反应。一个能正确捕捉一般荷载模式下土体特性的土材料模型是解决边界值岩土工程问题这类复杂工程问题所必需的。现有的实验室测试假设代表单一元素和应力-应变路径，不涵盖边界值问题中经历的全部加载路径，并且通常不足以验证材料模型在一般加载条件下的性能。该研究项目将开发一个综合计算-实验实验室测试框架。在此框架内，实验室测试将被视为边值问题，而不是单一元素测试。该测试与进化逆分析方法相结合，该方法将允许提取在该边值问题中产生的大量应力-应变路径。根据这些信息可以生成特定于土壤的材料本构模型。该试验装置是对广泛使用的三轴电池的改进。除摩擦帽外，该装置还包括侧向约束，以在土试样内诱导非均匀应力-应变状态。该装置将与成像技术相结合，以捕捉加载过程中试样的三维变形形状。新的反分析算法SelfSim使用一种进化材料本构模型从测量的边界载荷和变形中提取不同的应力-应变状态。本构模型可直接用于岩土工程问题的数值分析（如有限元法）。所提出的研究将为快速、实用和更全面的土壤行为表征打开新的和令人兴奋的大门。提出的框架有可能改变岩土工程以外的材料测试和表征。该项目将支持研究生和本科生的研究人员，并将为未来的工程师提供培训。