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.

该奖项根据 2009 年《美国复苏和再投资法案》（公法 111-5）提供资金。该奖项是 NSF 09-524 计划征集“George E. Brown, Jr. 地震工程模拟 (NEES) 研究网络 (NEESR)”的成果。 该奖项包括加州大学伯克利分校（领衔）和加州理工州立大学（子奖项）。 这项研究利用了加州大学戴维斯分校的 NEES 岩土离心机。 学术价值：这项研究的主要目标是推进地震期间作用在挡土结构上的动力的分析模型。目前使用的方法是从 1920 年代日本的工作开始逐渐演变的。然而，当时使用的实验方法无法准确地表示结构的真实行为，导致设计建议现在非常保守，并导致昂贵的过度设计。 这项研究利用最先进的实验研究设施，更好地了解地震期间土壤和挡土结构如何相互作用。该研究以最近完成的两个动态离心机实验系列为基础，由湾区捷运 (BART) 和山谷交通管理局 (VTA) 资助，以验证他们的设计假设。这项工作的结果表明，目前接受的一些基本假设与观察到的行为不符。因此，本研究的目的是通过进行一系列高质量的土工离心机模型试验来测量嵌入墙上的动态侧向土压力，从而对该问题进行全面的研究。离心机非常适合这种建模，因为缩放和边界条件允许对土壤行为进行正确的建模，并且离心机模型相对便宜且可重复。这项研究还提供了一个重新定义物理测试在动态土壤-结构相互作用问题新认识中的作用的机会。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，并开发适合基于性能的设计的概率程序。更广泛的影响：已经完成的工作已被实践工程师和为 BART 和 VTA 节省了大量成本。已完成工作的结果还表明，过去对纯分析解决方案和小规模振动台测试的依赖导致了与物理现实无关的代码和设计建议。岩土地震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的思维和新的解决方案。最终，思维和方法的改变可能会对岩土地震工程的所有领域产生重大影响。 该项目的数据将被存档并通过 NEES 数据存储库向公众开放。