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: 8922868
• 负责人: Raymond Seed
• 金额: $ 5.97万
• 依托单位: University of California-Berkeley
• 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: 1989-11-15 至 1991-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922868&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 University of California at Berkeley.

当受到强烈的地面震动时，例如在地震期间发生的震动，水饱和的沙土很容易液化。液化土壤的承载强度会降低，这可能导致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液化的分析。由于这种核查所需的实地数据极难获得，因此目前使用的数据是在土工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，在岩土工程研究界得到了广泛的接受。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：在这项研究中，仍有待回答的问题正在得到解决。不同的土工结构，包括坡地、水坝、海岸堤防和堤防，正在进行调查，以验证液化分析方法对各种土工结构的适用性。A类预测——包括在不知道测量结果的情况下预测土壤反应——用于以后与测量结果进行比较。地球技术公司负责管理该项目，提供精心校准的土壤样本，监督测试程序，并负责接收、分发和记录数据。与评审委员会合作。它还负责管理预测研究。评审委员会是一个独立的督导小组。参与研究的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、普林斯顿大学和剑桥大学。英格兰。总的来说，他们正在研究液化机制、分析和数值模型的发展和验证、有限和大变形条件下的土壤-结构相互作用、以及不同渗透性土层间界面的影响。该研究将有助于提高对土壤液化现象的认识，并提高用于预测液化发生及其对结构破坏的方法的可靠性。这一行动是为了支持加州大学伯克利分校的项目。