SGER: NEESR Payload Project for NSF Award 0420347 - Control of Plastic Hinging Behavior of RC Bridge Systems

SGER：获得 NSF 奖 0420347 的 NEESR 有效负载项目 - RC 桥梁系统塑性铰链行为的控制

• 批准号: 0532084
• 负责人: JoAnn Browning
• 金额: --
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0532084&HistoricalAwards=false
• 关键词: SGER; NEESR; Payload; Project; NSF

Abstract0532084SGER: NEESR Payload Project for NSF Award #0420347 -Control of Plastic Hinging Behavior of RC Bridge SystemsThe focus of this NEES Research (NEESR) payload project is to accurately model and control plastic hinging locations in concrete bridge structures through an investigation of actual hinging behavior in large-scale testing of bridge systems subjected to multiple excitations that includes the effects of joint and foundation flexibility. Models that are created to represent the hinging behavior in reinforced concrete systems, and the resulting understanding of this behavior under different loading conditions, have traditionally been limited by the ability to validate the model with experimental data - either from pre-existing bridge structures with inadequate access to internal reinforcement, or from component tests that are unable to simulate realistic boundary conditions. The validation of these detailed models is now possible with the data that will be collected during the NEESR project CMS-0420347 investigation of the seismic performance of four-span large-scale bridge systems, which includes the soil-foundation-structure interaction effects at the footings and abutments, at the NEES equipment site at the University of Nevada, Reno (UNR). The proposed NEESR payload research will be conducted in two parts: (1) small additions to the existing experimental procedure of the UNR NEESR team in the form of additional instrumentation, non-invasive photogrammetric methods, and additional input ground motions (at low level excitation), and (2) an analytical investigation of the effects of joint and foundation flexibility and load history on the control of plastic hinging locations in bridge systems. The specific goals of the project are the following: (1) accurately track the deformations in the hinging region and beam-column joints using traditional reinforcement and concrete gages as well as photogrammetric methods, (2) create a bridge system model using OpenSees that captures the joint deformations and spread of plasticity in the column elements under different levels of excitation, (3) compare deformations captured using traditional gages with those determined using photogrammetric methods, (4) perform parametric analysis of bridge systems with varied stiffness and strength properties to determine the effect on inelastic behavior, component, and system performance, (5) recommend simple techniques for calculating the drift response of bridge systems considering joint flexibility and more accurate plastic hinge behavior, and (6) engage graduate and undergraduate students through content in graduate courses and participation by telepresence during the testing phases of the project. Intellectual Merit: This proposal addresses the estimation of element and system level inelastic deformations considering the impact of joint and foundation flexibility for reinforced concrete bridge systems subjected to various strong ground motion demands. As part of this work, an improved joint model for reinforced concrete bridge systems will be developed for the OpenSees platform. The drift response of structural systems will be estimated with a better understanding of the contributions of joint flexibility and inelastic behavior in the elements. Broader Impacts: This project broadens the focus of a NEESR award that evaluates soil-foundation-structure interaction of reinforced concrete bridge systems and new hinging devices, to the contributions of joint flexibility to the development and the location of hinging in bridge elements. Undergraduate and graduate students will participate in the work through telepresence during testing and through graduate coursework.

摘要0532084SGER：获得 NSF 奖#0420347 的 NEESR 有效负载项目 - RC 桥梁系统塑性铰接行为的控制该 NEES 研究 (NEESR) 有效负载项目的重点是通过调查桥梁系统在多重激励下的大规模测试中的实际铰接行为（包括接头和基础柔性的影响），精确建模和控制混凝土桥梁结构中的塑性铰接位置。 为表示钢筋混凝土系统中的铰接行为而创建的模型，以及由此产生的对不同载荷条件下这种行为的理解，传统上受到用实验数据验证模型的能力的限制——要么来自无法充分访问内部钢筋的现有桥梁结构，要么来自无法模拟真实边界条件的组件测试。 现在可以利用 NEESR 项目 CMS-0420347 调查四跨大型桥梁系统的抗震性能期间收集的数据来验证这些详细模型，其中包括在内华达大学里诺分校 (UNR) 的 NEES 设备现场的基础和桥台处的土壤-基础-结构相互作用效应。拟议的 NEESR 有效载荷研究将分两部分进行：（1）以额外仪器、非侵入性摄影测量方法和额外输入地面运动（低水平激励）的形式对 UNR NEESR 团队现有实验程序进行少量补充，以及（2）对接头和基础灵活性以及载荷历史对桥梁系统中塑料铰接位置控制的影响进行分析研究。 该项目的具体目标如下：(1) 使用传统钢筋和混凝土量具以及摄影测量方法准确跟踪铰接区域和梁柱接头的变形，(2) 使用 OpenSees 创建桥梁系统模型，捕获不同激励水平下柱单元的接头变形和塑性扩展，(3) 将使用传统量具捕获的变形与使用摄影测量方法确定的变形进行比较， (4) 对具有不同刚度和强度特性的桥梁系统进行参数分析，以确定对非弹性行为、组件和系统性能的影响，(5) 考虑关节灵活性和更准确的塑性铰链行为，推荐计算桥梁系统漂移响应的简单技术，(6) 通过研究生课程内容和项目测试阶段的远程呈现吸引研究生和本科生参与。 智力优点：该提案解决了单元和系统级非弹性变形的估计问题，考虑到钢筋混凝土桥梁系统在各种强烈地面运动要求下的接头和基础灵活性的影响。作为这项工作的一部分，将为 OpenSees 平台开发一种改进的钢筋混凝土桥梁系统接头模型。通过更好地理解单元中关节灵活性和非弹性行为的贡献，可以估计结构系统的漂移响应。 更广泛的影响：该项目扩大了 NEESR 奖项的重点，该奖项评估钢筋混凝土桥梁系统和新型铰链装置的土壤-基础-结构相互作用，以及接头灵活性对桥梁元件中铰链开发和位置的贡献。本科生和研究生将通过测试期间的远程呈现和研究生课程参与工作。