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: 9800318
• 负责人: Thomas Sheahan
• 金额: --
• 依托单位: Northeastern University
• 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=9800318&HistoricalAwards=false
• 关键词: New; Experimental; Approach; Toward; Unified

9800318 Sheahan "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 inst rumented consolidation cell was developed under a prior NSF award. This device will be used to perform controlled gradient tests with feedback provided by mid-specimen pore pressure probes. ***

9800318 Sheahan “实现随时间固结统一理论的新实验方法” 这项研究涉及一种创新的实验方法，有助于解决岩土工程中的一个基本问题：固结过程中随时间蠕变变形的作用。 细粒土的原始固结理论无法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，包括难以根据实验室测试预测现场固结沉降。 它还引发了关于固结过程中蠕变性质的研究和争论。 一种假设预测，在所有加载引起的孔隙水压力消散之前，蠕变变形不会产生影响； 另一个假设包括整个整合过程中的蠕变。 这两种理论都有大量的数据和著名的研究人员支持，但它们之间的一致性却很少。 这项研究将调查整合模型的有效性，该模型有可能统一这两个假设并解释两组明显冲突的数据。 这项研究的目的不是证明其中一个假设，而是为了测量每个固结成分（由于孔隙压力耗散和蠕变）对整体行为的贡献。 该研究将通过东北大学和马萨诸塞大学阿默斯特分校之间的合作伙伴关系进行。 马萨诸塞大学阿默斯特分校合作伙伴将获得四种天然土壤的高质量块样本，每种土壤都有自己的特定结构，并将进行短期和长期常规增量加载测试，以评估蠕变行为和常规固结参数。 在东北大学，根据先前的 NSF 奖项开发了一个计算机自动化、专门配备仪器的固结单元。 该设备将用于执行受控梯度测试，并由中间样本孔隙压力探头提供反馈。 ***