Laboratory Qualification and Field Behavior Studies of Piezometers for Measuring Earthquake-Induced Pore Pressures

用于测量地震引起的孔隙压力的测压计的实验室资格和现场行为研究

• 批准号: 9709334
• 负责人: Pedro de Alba
• 金额: $ 13.82万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-15 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9709334&HistoricalAwards=false
• 关键词: Laboratory; Qualification; Field; Behavior; Studies

Abstract: CMS-9709334, Pedro deAlba & Jean Benoit, University of New Hampshire When a saturated sand deposit is shaken by an earthquake, there can be a significant build-up of pore-water pressure, with consequent loss of rigidity and strength of the soil, often ending in actual liquefaction of the deposit, and major damage to structures. While pore-pressure buildup has been simulated in laboratory experiments, there is only one case currently available in which the development of these pore pressures to the point of liquefaction was measured in a field deposit under earthquake-induced strong-ground shaking. Unfortunately, the pore pressure records obtained in this case have certain unusual features, which has led some researchers to question their validity. Consequently, it is of primary importance to geotechnical earthquake engineers to obtain more records, in order to provide a final verification of mathematical models developed on the basis of laboratory and centrifuge testing. This research project involves an extensive laboratory and field study of piezometer designs in current use. In the laboratory, piezometer installation will be simulated in a test chamber, and piezometer response to dynamic pore pressure increases will be measured both in water alone and in saturated soil. Acceptable procedures for design, saturation and installation of piezometers will thus be identified. In the second phase, a field installation for periodically checking piezometer response will be developed. These second-phase tests will provide insight into the problem of response changes, if any, due to long-term biological or chemical interaction with the surrounding soil. The outcome of this project will be a set of guidelines for the design, manufacture, installation and long-term monitoring of piezometer arrays designed to obtain much-needed field data on pore pressure development during earthquakes. This project is being coordinated with a complementa ry research program headed by Dr. Behnam Hushmand of Hushmand Associates, California.

摘要：CMS-9709334，Pedro deAlba 和 Jean Benoit，新罕布什尔大学 当饱和砂沉积物因地震而摇动时，孔隙水压力可能会显着增加，从而导致土壤硬度和强度损失，通常最终导致沉积物实际液化，并对结构造成重大损坏。虽然在实验室实验中模拟了孔隙压力的增加，但目前只有一种情况是在地震引起的强烈地面震动下，在现场沉积物中测量到这些孔隙压力发展到液化点的情况。不幸的是，在这种情况下获得的孔隙压力记录具有某些不寻常的特征，这导致一些研究人员质疑其有效性。因此，对于岩土地震工程师来说，获得更多的记录至关重要，以便为基于实验室和离心机测试的数学模型提供最终验证。 该研究项目涉及对当前使用的压力计设计进行广泛的实验室和现场研究。在实验室中，将在测试室中模拟渗压计的安装，并在单独的水中和饱和土壤中测量渗压计对动态孔隙压力增加的响应。从而确定可接受的渗压计设计、饱和度和安装程序。在第二阶段，将开发用于定期检查压力计响应的现场装置。这些第二阶段的测试将深入了解由于与周围土壤的长期生物或化学相互作用而导致的响应变化问题（如果有的话）。 该项目的成果将是一套用于设计、制造、安装和长期监测测压计阵列的指南，旨在获取地震期间孔隙压力发展急需的现场数据。 该项目正在与加利福尼亚州 Hushmand Associates 的 Behnam Hushmand 博士领导的补充研究计划进行协调。