Upgrading the National Geotechnical Centrifuge

升级国家土力离心机

• 批准号: 8714727
• 负责人: Bruce Kutter
• 金额: $ 29.9万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-15 至 1990-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8714727&HistoricalAwards=false
• 关键词: Upgrading; National; Geotechnical; Centrifuge

This action is to provide funds for the construction of an enclosure to the National Geotechnical Centrifuge. Centrifuge modeling is a useful tool for studying a wide variety of geotechnical earthquake engineering problems. The state of stress and strain in an earth structure is dependent upon the overburden pressure, which is analogous to the hydrostatic pressure which increases with depth in a body of water. This overburden pressure is a result of gravitational loading. When testing a scale model of an earth structure, this gravitational loading must be correctly scaled, and this requires that gravity be increased in proportion to the reduction in the scale of the model: a half-scale model has to be subjected to twice the normal gravity loading. This increase in gravity loading can be obtained by testing the scale model in a centrifuge. The National Geotechnical Centrifuge was donated by NASA AMES to the University of California at Davis. It has been converted for use as a geotechnical engineering centrifuge, and more recently it was moved to the Davis campus. It is now operational at the new location, but funds were not available to provide a roof for the enclosure. As a result, the centrifuge is operating in the open air, which severely limits the capacity of the machine due to windage losses: as the arm turns it acts as a large centrifugal fan. These windage losses are unavoidable, but they can be reduced significantly by appropriate design of the enclosure. For the National Geotechnical Centrifuge, the open pit installation performance can be increased from 100 g-tons to 500 g-tons by installing a suitably designed enclosure. The increased performance provides a capacity which is sorely needed in the United States. Researchers needing this capacity must currently perform their tests on a centrifuge in Cambridge, England. This is both costly and slow. The construction of an enclosure for the National Geotechnical Centrifuge will provide a facility that will increase dramatically the experiments that can be performed in geotechnical engineering, in particular in earthquake engineering.

该行动是为建造国家岩土工程离心机的围栏提供资金。 离心机建模是研究各种岩土技术工程问题的有用工具。地球结构中的应力和应变状态取决于覆盖压力，这类似于静水压力，该压力随着水体中的深度而增加。这种覆盖的压力是重力负荷的结果。当测试地球结构的比例模型时，必须正确缩放此重力负载，这要求重力与模型尺度的减小成比例增加：半尺度模型必须承受正常重力负载的两倍。可以通过在离心机中测试比例模型来获得重力负载的增加。 国家岩土工程离心机由美国国家航空航天局（NASA AMES）捐赠给加利福尼亚大学戴维斯分校。它已转换为用作岩土工程离心机，最近它被移至戴维斯校园。现在它在新地点运行，但是资金无法为围墙提供屋顶。结果，离心机在露天中运行，这严重限制了由于风能损失而导致的机器的容量：随着手臂的转动，它充当大型离心风扇。这些风格损失是不可避免的，但是可以通过适当的外壳设计来显着减少它们。对于国家岩土工程离心机，通过安装适当设计的外壳，可以将开放坑安装性能从100 g吨提高到500 g-吨。提高的性能提供了在美国迫切需要的能力。目前需要此能力的研究人员必须在英格兰剑桥的一个离心机上进行测试。这既昂贵又慢。 为国家岩土工程离心机建造围栏将提供一个设施，该设施将大大增加可以在岩土工程中进行的实验，特别是在地震工程中。