Studies of an Earthquake Simulator for the Large Geotechnical Centrifuge at Davis, California

离心机模型是研究各种岩土地震工程问题的一种有用的技术。土工结构的离心机模型可以被仔细地测量，并以可重复和现实的方式经受极端的--即设计水平--加载条件。具体地说，它们可以受到模拟的大地震的影响。这有可能提供从遭受自然发生的大地震的全尺寸岩土结构中获得的数据，这些数据是极其困难的--而且很少可能获得。这种地震模拟能力已经在美国的五个学术机构获得，但到目前为止，只有小的岩土模型可以受到模拟地震的影响。伦斯勒理工学院的研究人员目前正在设计一种摇床，它将允许在该研究所的中型离心机上使用中型模型。这一行动是为了支持加州大学戴维斯分校大型土工离心机的地震模拟器的设计研究。这个模拟器将有能力使大型模型受到模拟地震的影响。这种离心机的独特之处在于它的桶大小(计划为6英尺乘7英尺)，可以在大型模型上进行实验。可以测试的大型模型允许：(1)使用更多的工具，同时最大限度地减少工具对模型行为的影响；(2)模型中可以包括精细的细节；以及(3)在较低比例因子下进行测试的可能性，以最大限度地减少比例效应并扩大模型的建模范围(一种验证小规模模型能够准确地模拟完整尺度行为的技术)。这项设计研究由一个由其他机构的专家组成的监督委员会监督。监督委员会将进行单独的设计研究；这些项目与本奖项支持的项目相结合，有望有效地解决与设计大型离心机地震模拟设施相关的极具挑战性的问题。

Centrifuge modeling is a useful technique for studying a wide variety of geotechnical earthquake engineering problems. Centrifuge models of geotechnical structures can be carefully instrumented and subjected to extreme - that is, design level - loading conditions in a repeatable and realistic manner. Specifically, they can be subjected to simulated large earthquakes. This has the potential to provide data that are extremely difficult - and rarely possible - to obtain from full-scale geotechnical structures subjected to naturally occurring large earthquakes. This earthquake simulation capability is already available at five academic institutions in the U.S., but to date only small geotechnical models can be subjected to simulated earthquakes. Researchers at the Rensselaer Polytechnic Institute are currently designing a shaker which will permit the use of intermediate-sized models on the intermediate- sized centrifuge at that institution. This action is to support design studies for an earthquake simulator for the large geotechnical centrifuge at the University of California at Davis. This simulator would have the capacity to subject large models to simulated earthquakes. The unique feature of this centrifuge is its bucket size (6 feet by 7 feet in plan), which permits experiments to be conducted on large models. The large models that can be tested permit: (1) use of more instrumentation while minimizing the influence of instrumentation on model behavior; (2) fine details can be included in the model; and (3) the possibility of conducting tests at lower scale factors to minimize scale effects and to extend the range of modeling of models (a technique to verify that small-scale models are capable of modeling accurately the full-scale behavior). This design study is monitored by an Oversight Committee composed of experts from other institutions. The Oversight Committee will undertake separate design studies; which, when combined with those supported by this award, are expected to address effectively the extremely challenging problems associated with the design of a large centrifuge earthquake simulation facility.