Verification of Soil Liquefaction Analysis by Coordinated Geotechnical Centrifuge Studies

通过协调岩土离心机研究验证土壤液化分析

• 批准号: 9000390
• 负责人: Ronald Scott
• 金额: $ 25.56万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 1994-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9000390&HistoricalAwards=false
• 关键词: Verification; Soil; Liquefaction; Analysis; Coordinated

Water-saturated sandy soils are susceptible to liquefaction when subjected to strong ground shaking, such as occurs during an earthquake. Liquefied soils experience a decrease in bearing strength: this can lead to the partial or total collapse of buildings standing on liquefied soils. The aim of this project is to verify the analyses used to predict liquefaction due to earthquake loading. Since the field data needed for this verification is extremely difficult to obtain, data is being used instead from laboratory experiments performed on geotechnical centrifuges. This is a relatively new technique for soil testing which is becoming well accepted in the geotechnical research community. The technique for simulating earthquakes on centrifuges is being developed, and the results obtained have generated confidence in the method: questions that remain to be answered are being addressed in this study. Different geotechnical structures, including sloping ground, dams, coastal dikes, and embankments are being investigated so as to validate the applicability of the liquefaction analysis methods to a variety of geotechnical structures. Class A predictions - which involve predicting the soil response without knowing the measured results - are used for later comparison with measured results. The Earth Technology Corporation is responsible for the management of the project, for providing carefully calibrated soil samples, for overseeing the testing program, as well as being responsible for receiving, distributing and documenting data, in conjunction with the Adjudication Committee. It is also responsible for managing the prediction studies. The Adjudication Committee acts as an independent steering group. The participating institutions are the University of California at Davis and Berkeley, the California Institute of Technology, the University of Colorado, the Massachusetts Institute of Technology, Princeton University, and Cambridge University, England. Collectively, they are examining the mechanisms of liquefaction, the development and verification of analytical and numerical models, soil-structure interaction for conditions of limited and large deformations, and the effect of interfaces between soil layers of differing permeabilities. This study will contribute significantly to improving the understanding of the soil liquefaction phenomenon, and to the reliability of methods used to predict the occurrence of liquefaction and the resulting damage to structures. This action is for support of the program at the California Institute of Technology.

当遭受强烈的地面震动（例如地震期间发生的震动）时，水饱和的沙土很容易液化。 液化土壤的承载强度会下降：这可能导致位于液化土壤上的建筑物部分或全部倒塌。 该项目的目的是验证用于预测地震荷载引起的液化的分析。 由于该验证所需的现场数据极难获得，因此使用的数据来自在岩土离心机上进行的实验室实验。 这是一种相对较新的土壤测试技术，已被岩土研究界广泛接受。 在离心机上模拟地震的技术正在开发中，所获得的结果使人们对该方法产生了信心：本研究正在解决仍有待回答的问题。 正在研究不同的岩土结构，包括坡地、水坝、沿海堤坝和路堤，以验证液化分析方法对各种岩土结构的适用性。 A 类预测（涉及在不知道测量结果的情况下预测土壤响应）用于以后与测量结果进行比较。 地球技术公司负责项目的管理，提供仔细校准的土壤样本，监督测试计划，并与评审委员会一起负责接收、分发和记录数据。 它还负责管理预测研究。 评审委员会作为一个独立的指导小组。 参与机构包括加州大学戴维斯分校和伯克利分校、加州理工学院、科罗拉多大学、麻省理工学院、普林斯顿大学和英国剑桥大学。 总的来说，他们正在研究液化机制、分析和数值模型的开发和验证、有限和大变形条件下的土壤-结构相互作用，以及不同渗透率土层之间界面的影响。 这项研究将极大地有助于提高对土壤液化现象的理解，并提高用于预测液化发生及其对结构造成的损害的方法的可靠性。 此举是为了支持加州理工学院的该项目。