A New Experimental Approach Toward A Unified Theory of Time-Dependent Consolidation

时变固结统一理论的新实验方法

• 批准号: 9812106
• 负责人: Don DeGroot
• 金额: $ 5.58万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9812106&HistoricalAwards=false
• 关键词: New; Experimental; Approach; Toward; Unified

9812106 DeGroot "A New Experimental Approach Toward a Unified Theory of Time- Dependent Consolidation" This research involves an innovative experimental approach to help resolve a fundamental issue in geotechnical engineering: the role of time-dependent creep deformations during consolidation. The original consolidation theory for fine-grained soils cannot predict the influence of creep deformations that occur under constant effective stress levels. This has led to significant practical problems, including difficulty in predicting field consolidation settlements based on laboratory tests. It has also led to research and debate on the nature of creep during consolidation. One hypothesis predicts no influence of creep deformations until after all loading- induced pore water pressures are dissipated; the other hypothesis includes creep throughout the consolidation process. There are substantial data and prominent researchers supporting each of the two theories, but little agreement between them. This research will investigate the validity of a consolidation model that can potentially unify the two hypotheses and explain both sets of apparently conflicting data. This research is not aimed at proving one of the hypotheses, but toward measuring the contribution of each consolidation component (due to pore pressure dissipation and due to creep) to the overall behavior. The research will be executed through a partnership between Northeastern University and the University of Massachusetts- Amherst. The UMASS- Amherst partner will obtain high quality block samples of four natural soils, each with its own particular structure, and will perform short- and long-term conventional, incrementally loaded tests to evaluate creep behavior and conventional consolidation parameters. At Northeastern, a computer-automated, specially instrumented consolidation cell was developed under a prior NSF award. This device will be used to perform controlle d gradient tests with feedback provided by mid-specimen pore pressure probes. ***

小行星9812106 “固结时间相关统一理论的一种新的实验方法” 这项研究涉及一种创新的实验方法，以帮助解决岩土工程中的一个基本问题：固结过程中随时间变化的蠕变变形的作用。 细粒土的原始固结理论不能预测在恒定有效应力水平下发生的蠕变变形的影响。 这导致了重大的实际问题，包括难以预测现场固结沉降的基础上，实验室测试。 这也导致了对固结过程中蠕变性质的研究和辩论。 一种假设认为，在所有荷载引起的孔隙水压力消散之前，蠕变变形不会产生影响;另一种假设认为，蠕变贯穿于整个固结过程。 这两种理论都有大量的数据和杰出的研究人员支持，但它们之间的一致性很小。 本研究将探讨一个整合模型的有效性，该模型可以潜在地统一这两个假设，并解释两组明显矛盾的数据。 这项研究的目的不是为了证明其中一个假设，而是为了测量每个固结分量（由于孔隙压力消散和蠕变）对整体行为的贡献。 这项研究将通过东北大学和马萨诸塞州大学-阿默斯特分校的合作进行。 UMASS-阿默斯特合作伙伴将获得四种天然土壤的高质量块体样品，每种土壤都有其特定的结构，并将进行短期和长期的常规增量加载试验，以评估蠕变行为和常规固结参数。 在东北大学，一个计算机自动化的，专门仪器化的巩固单元是根据先前的NSF奖。 该装置将用于执行受控梯度测试，并通过中间试样孔隙压力探头提供反馈。 ***