NEESR-CR: Seismic Earth Pressures on Retaining Structures

NEESR-CR：挡土结构上的地震土压力

• 批准号: 0936376
• 负责人: Nicholas Sitar
• 金额: $ 51.97万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0936376&HistoricalAwards=false
• 关键词: NEESR; CR; Seismic; Earth; Pressures

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)." This award includes the University of Calfornia, Berkeley (lead), and California Polytechnic State University (subaward). This research utilizes the NEES geotechnical centrifuge at the University of California at Davis.Intellectual Merit: The main objective of this research is to advance the analytical modeling of the dynamic forces acting on earth retaining structures during earthquakes. The methods currently in use have evolved gradually starting with Japanese work performed in the 1920's. However, the experimental methods used at the time were not capable of accurately representing the real behavior of structures and resulted in design recommendations that are now very conservative and that lead to expensive over design. This research takes advantage of the most advanced experimental research facilities to develop a better understanding of how soil and retaining structures interact during earthquakes. The research builds on recently completed series of two dynamic centrifuge experiments funded by the Bay Area Rapid Transit (BART) and the Valley Transportation Authority (VTA) in order to verify their design assumptions. The results of this work show that some of the basic assumptions currently accepted as given do not match the observed behavior. Hence, the purpose of this research is to produce a comprehensive study of the problem by performing a series of high quality geotechnical centrifuge model tests to measure dynamic lateral earth pressures on embedded walls. The centrifuge is ideally suited for this kind of modeling because the scaling and boundary conditions allow for correct modeling of the soil behavior, and centrifuge models are relatively inexpensive and reproducible. This research also presents an opportunity to redefine the role of physical testing in the development of new understanding of dynamic soil-structure interaction problems. The results of the physical experiments will be used in the latest generation of non-linear code to produce better modeling and predictive capabilities and to develop probabilistic procedures suitable for performance based design.Broader Impacts: The work already completed has been adopted by practicing engineers and has resulted in significant cost savings for BART and VTA. The results of the already completed work also show that past reliance on purely analytical solutions and on small scale shaking table tests has resulted in code and design recommendations that have no connection with the physical reality. Similar problems exist in other aspects of geotechnical earthquake engineering and new methods of modeling and analysis are needed to produce fresh thinking and fresh solutions. Ultimately the change in thinking and methodology could have a significant impact in all areas of geotechnical earthquake engineering. Data from this project will be archived and made available to the public through the NEES data repository.

该奖项是根据2009年《美国复苏与再投资法》（公法111-5）资助的。该奖项是NSF 09-524计划招标的结果“乔治·E·布朗，小地震工程模拟网络（NEES）研究（NEESR）。” 该奖项包括卡尔福尼亚大学，伯克利大学（Lead）和加利福尼亚理工大学（Subaward）。 这项研究利用加利福尼亚大学戴维斯分校的NEE岩土离心机。智能优点：这项研究的主要目的是推进对地震期间在地球保留结构上作用的动态力的分析模型。目前正在使用的方法逐渐从1920年代的日本作品开始。但是，当时使用的实验方法无法准确代表结构的真实行为，并导致了现在非常保守的设计建议，并且导致了昂贵的设计。 这项研究利用了最先进的实验研究设施，以更好地了解土壤和保留在地震期间的相互作用。该研究基于最近完成的两个动态离心机实验系列，这些实验由海湾地区快速运输（BART）和山谷运输局（VTA）资助，以验证其设计假设。这项工作的结果表明，当前接受为给定的一些基本假设与观察到的行为不符。因此，这项研究的目的是通过执行一系列高质量的岩土离心机模型测试来对问题进行全面研究，以测量嵌入式壁上的动态横向压力。离心机非常适合这种建模，因为缩放和边界条件允许正确建模土壤行为，并且离心机模型相对便宜且可再现。这项研究还提供了一个机会，可以重新定义物理测试在对动态土壤结构问题的新理解中的发展中的作用。物理实验的结果将用于最新一代的非线性代码，以产生更好的建模和预测能力，并开发适合基于绩效的设计的概率程序。Broader的影响：实践工程师已经完成了已经完成的工作，并导致了Bart和VTA的大量成本节省。已经完成的工作的结果还表明，过去对纯粹分析解决方案和小规模摇桌测试的依赖导致了与物理现实无关的代码和设计建议。岩土技术工程的其他方面也存在类似的问题，需要新的建模和分析方法来产生新鲜的思维和新鲜解决方案。最终，思维和方法论的变化可能会在岩土技术工程的所有领域产生重大影响。 该项目的数据将通过NEES数据存储库进行存档并提供给公众。