EAGER: Informing Infrastructure Decisions through Large-Amplitude Forced Vibration Testing

EAGER：通过大振幅受迫振动测试为基础设施决策提供信息

• 批准号: 1650170
• 负责人: Nenad Gucunski
• 金额: $ 23.53万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1650170&HistoricalAwards=false
• 关键词: EAGER; Informing; Infrastructure; Decisions; through

The societal problems presented by aging civil infrastructures in the US are pervasive - cutting across diverse structures associated with our flood protection systems, existing building stock, and transportation networks. In recognition of the life safety risks posed by such systems under natural and anthropogenic hazards, there has been significant attention paid to the development of reliable safety assessment approaches to support their management, adaption, and reuse. What began with a near-exclusive reliance on visual inspections and simplified simulation models has evolved over the last several decades to embrace the impressive array of sensing technologies, highly refined simulation models, and model calibration techniques now available. Although these advances are significant, there remains no approach capable of assessing the safety of both the structure and the foundation system in a reliable manner. The aim of this EArly-concept Grant for Exploratory Research (EAGER) project is to overcome this barrier through the use of large amplitude shakers that were originally envisioned for evaluating soil properties. If this re-purposing of these large shakers proves successful, this research will remove a critical barrier to our ability to forecast the service life of existing infrastructure systems and, in turn, to make sound decisions about their adaption and reuse. In addition to this technical contribution, this research will expose and attract high schools students to engineering (through the development and implementation of a competition based outreach effort) and will recruit graduate students (who will be supported through project funds) from traditionally underrepresented groups through a host of on-going programs at Rutgers University. The project aims overcoming limitations of existing dynamic testing methodologies for structural systems. While cost-effective methodologies exist, they suffer from a reliance on low-amplitude, uni-directional excitation, which is unable to overcome intermittent stick-slip mechanisms or to induce appreciable responses within the substructure-foundation system. Therefore, to overcome these low-level mechanisms in a controlled manner, and improve the reliability of the resulting safety assessment, the research team will use large-amplitude mobile shakers that are available through the NSF NHERI Program. Although originally envisioned for geotechnical engineering seismic-related research, such shakers open opportunities for pushing the structural-foundation system beyond their low-level responses to reveal performance characteristics that are more representative of the expected behavior under safety limit states. By overcoming the mechanisms that exist only at low-levels, a more realistic distribution of forces will be captured, which will greatly enhance the reliability of simulation model predictions associated with the onset (both load levels and spatial location) of material nonlinearity. To meet this overarching goal, the following more focused objectives will be pursued:(1) Develop, evaluate, and refine a series of forced vibration testing and control strategies to capture response measurements indicative of key performance attributes of substructure/foundation and superstructure systems.(2) Develop, evaluate, and refine a series of both model-free and model-based data interpretation frameworks for structural system (foundation-substructure-superstructure) identification and assessment.(3) Perform a validation of the testing/control strategies and data interpretation frameworks on an operating structure with known substructure, foundation, and soil characteristics

美国老化的民用基础设施所带来的社会问题是普遍存在的——涉及与我们的防洪系统、现有建筑群和交通网络相关的各种结构。 认识到此类系统在自然和人为危害下造成的生命安全风险，人们对开发可靠的安全评估方法以支持其管理、适应和再利用给予了极大的关注。 最初几乎完全依赖视觉检查和简化的仿真模型，在过去的几十年里已经发展到包含令人印象深刻的一系列传感技术、高度精细的仿真模型和现在可用的模型校准技术。 尽管这些进步意义重大，但仍然没有能够以可靠的方式评估结构和基础系统安全性的方法。 这个早期概念探索性研究资助 (EAGER) 项目的目的是通过使用最初设想用于评估土壤特性的大振幅振动台来克服这一障碍。 如果这些大型振动筛的重新利用被证明是成功的，这项研究将消除我们预测现有基础设施系统使用寿命的关键障碍，进而就其适应和再利用做出明智的决策。 除了这项技术贡献外，这项研究还将让高中生接触并吸引工程专业（通过开发和实施基于竞争的外展工作），并将通过以下方式从传统上代表性不足的群体中招募研究生（他们将通过项目资金获得支持）罗格斯大学正在进行的一系列项目。该项目旨在克服结构系统现有动态测试方法的局限性。 虽然存在具有成本效益的方法，但它们依赖于低幅度、单向激励，无法克服间歇性粘滑机制或在下部结构-基础系统内引起明显的响应。 因此，为了以受控方式克服这些低级机制，并提高最终安全评估的可靠性，研究团队将使用 NSF NHERI 计划提供的大振幅移动振动台。 尽管最初设想用于岩土工程地震相关研究，但此类振动台为推动结构基础系统超越其低水平响应提供了机会，以揭示更能代表安全极限状态下预期行为的性能特征。 通过克服仅存在于低水平的机制，将捕获更真实的力分布，这将大大提高与材料非线性发生（载荷水平和空间位置）相关的仿真模型预测的可靠性。 为了实现这一总体目标，将追求以下更集中的目标：（1）开发、评估和完善一系列受迫振动测试和控制策略，以捕获表明下部结构/基础和上部结构系统关键性能属性的响应测量。 (2) 开发、评估和完善一系列用于结构系统（基础-下部结构-上部结构）识别和评估的无模型和基于模型的数据解释框架。(3) 对测试/控制策略和数据解释具有已知下部结构、地基和土壤特性的运行结构上的框架

项目成果

Assessing the Significance of Dynamic Soil-Structure Interaction Using Large-Amplitude Mobile Shakers

使用大振幅移动振动台评估动态土壤-结构相互作用的意义

• 发表时间: 2019-04
• 期刊: ASCE
• 作者: Farrag, Sharef;Gucunski, Nenad;Cox, Brady;Menq, Farnyuh;Moon, Franklin;DeVitis, John
• 通讯作者: DeVitis, John

Inferring Dynamic Characteristics of a Bridge through Numerical Simulation and Low-Magnitude Shaking as a Global NDE Method

通过数值模拟和低强度振动作为全局 NDE 方法推断桥梁的动态特性

• 发表时间: 2018-07
• 期刊: 2018 SMT and NDE-CE ASNT Topical Conference
• 作者: Farrag, Sharef;Gucunski, Nenad;Moon, Franklin;DeVitis, John;Cox, Brady;Menq, Farnyuh
• 通讯作者: Menq, Farnyuh