Cyclic Loading Behavior of Fine-Grained Soils

细粒土的循环加载行为

• 批准号: 9502530
• 负责人: Ross Boulanger
• 金额: $ 28.2万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9502530&HistoricalAwards=false
• 关键词: Cyclic; Loading; Behavior; Fine; Grained

9502530 Boulanger The objective of this research project is to develop a fundamental framework for understanding and describing the behavior of "liquefiable" fine-grained soils subjected to cyclic and monotonic undrained loading -- a necessary step in the development of reliable design methodologies for assessing liquefaction potential of soils. The term "liquefiable" is used to denote fine-grained soils that would be considered susceptible to severe strength loss during earthquake loading. The primary task towards achieving this objective is a comprehensive laboratory study of select low-plasticity silts and clays over the wide range of conditions necessary to establish a fundamental framework. The project includes monotonic loading, cyclic loading, post-cyclic monotonic loading, and consolidation tests over a wide range of confining stresses and void ratios to investigate the interrelationships between the undrained loading behavior and the conditions of initial state, quasi-steady state, and steady state. It also includes an investigation of the influence of sample preparation method, stress history, and loading path (i.e., triaxial versus torsional shear) over a wide range of void ratios and confining stresses The results of this study will fill a vital gap in the understanding of the behavior of fine-grained soils during earthquake loading, and thereby assist in the development of engineering procedures for assessing potential earthquake hazards related to the earthquake loading response of fine-grained soils. EDUCATION PLAN The objective of the education plan is to equip civil engineering students with a sound philosophy of engineering, a rigorous grounding in engineering basics and fundamentals, and an appreciation of the complementary roles of theory and judgment. The education plan covers several details which will enhance the basic strength of the existing curriculum, and thereby contribute to an inspiring, well-rounded education in civil and environmental engineering. It includes the following items: In design courses, have a practicing professional assist in setting up the design project, and then discuss alternative designs at the end of the course; select these and other new course projects to illustrate the complementary roles of fundamental theory and engineering judgment in the practice of civil and environmental engineering; develop an instructional video on drilling and sampling procedures for site characterization; introduce computer- based data-acquisition systems into the undergraduate laboratory curriculum; involve undergraduates in research projects via summer employment and independent research electives; and introduce results from recent research in appropriate courses ***

9502530 Boulanger本研究项目的目标是开发一个基本框架，用于理解和描述“可液化”细粒土在循环和单调不排水荷载下的行为-这是开发可靠的设计方法评估土壤液化潜力的必要步骤。 术语“可液化”用于表示细粒土，认为其在地震荷载作用下易受严重强度损失的影响。实现这一目标的主要任务是在建立基本框架所需的广泛条件下对选择的低塑性粉土和粘土进行综合实验室研究。该项目包括单调加载，循环加载，循环后单调加载，并在广泛的围压和孔隙比的固结试验，以调查不排水加载行为和初始状态，准稳定状态和稳定状态的条件之间的相互关系。 它还包括对样品制备方法、应力历史和加载路径（即，三轴与扭转剪切）在很宽的孔隙比和围压范围内 这项研究的结果将填补一个重要的空白，在地震荷载作用下的细粒土的行为的理解，从而有助于开发工程程序，用于评估潜在的地震灾害有关的细粒土的地震荷载响应。 教育计划 教育计划的目标是使土木工程专业的学生具备良好的工程哲学，严格的工程基础和基本原理，以及对理论和判断的互补作用的理解。 教育计划涵盖了几个细节，这将提高现有课程的基本实力，从而有助于在土木和环境工程的启发性，全面的教育。 它包括以下项目：在设计课程中，有一个实践的专业协助建立设计项目，然后在课程结束时讨论替代设计，选择这些和其他新的课程项目，以说明基础理论和工程判断在土木和环境工程实践中的互补作用;制作一个关于场地特征鉴定的钻探和取样程序的教学录像带;在本科生实验室课程中引入计算机数据采集系统;通过暑期就业和独立研究选修课让本科生参与研究项目;并在适当的课程中介绍最近的研究成果 *