Verification of Soil Liquefaction Analysis by Coordinated Geotechnical Centrifuge Studies

饱水的砂质土壤在受到强烈的地面震动时很容易发生液化，例如地震期间。液化土的承载强度降低：这可能会导致建在液化土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。由于这一核查所需的现场数据极难获得，因此取而代之的是在土工离心机上进行的实验室实验的数据。这是一种相对较新的土壤测试技术，正在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：这项研究正在解决有待回答的问题。为了验证液化分析方法对各种岩土结构的适用性，正在对不同的岩土结构进行研究，包括斜坡、堤坝、海岸堤防和堤防。A类预测--包括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。地球技术公司负责该项目的管理，负责提供经过仔细校准的土壤样本，负责监督测试计划，并与裁决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。仲裁委员会是一个独立的指导小组。参与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，英国。他们共同研究液化的机理、分析和数值模型的开发和验证、有限和大变形条件下的土-结构相互作用、以及不同渗透率的土层间界面的影响。这项研究将有助于提高对土体液化现象的认识，以及预测液化发生和由此造成的结构破坏的方法的可靠性。这一行动是为了支持裁决委员会。保罗·汤普森教授是委员会主席。

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 Adjudication Committee. Professor Paul Thompson is the committee chair.