Analysis, Design and System-Level Performance of Repairable Precast Concrete Buckling-Restrained Braced Frames under Seismic Loads

地震荷载下可修复预制混凝土屈曲约束支撑框架的分析、设计和系统级性能

• 批准号: 2230187
• 负责人: Yahya Kurama
• 金额: $ 136.43万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2230187&HistoricalAwards=false
• 关键词: Analysis; Design; System; Level; Performance

The scale of losses from previous earthquakes has demonstrated the need for buildings that can rapidly restore their essential functions after a natural disaster. This concept is called functional recovery. This project will contribute to the nation’s functional recovery objectives by creating and examining a repairable precast concrete buckling-restrained braced (BRB) frame structure with a new type of non-proprietary diagonal brace. The new brace will have low-cost features that permit practical replacement after an earthquake. This project will generate fundamental knowledge on the seismic design and performance of this building system. Data will be generated from numerical analyses, testing of isolated braces and their connections, and culminating tests on the seismic performance and repair of a three-story building utilizing the six-degree-of-freedom Large High-Performance Outdoor Shake Table operated by the University of California, San Diego, as part of the NSF-funded Natural Hazards Engineering Research Infrastructure (NHERI). The project will emphasize diversity and inclusion, will engage undergraduates from underrepresented groups in education and mentoring programs, and will create engineering learning modules for pre-college students. Precast industry partners will provide specimens and technical guidance emphasizing the project’s focus on industry-preferred structural details for practical acceptance. Engagement with the broader engineering community will be achieved through a competition to predict the building response on the shake table. Data generated from this project will be archived and made publicly available in the NHERI Data Depot (https://www.DesignSafe-CI.org). This award will contribute to NSF's role in the National Earthquake Hazards Reduction Program (NEHRP). There is currently no comprehensive U.S.-based research on the seismic performance of precast BRB frame structures. This project will fill this research gap by 1) designing and characterizing the behavior of a novel, replaceable concrete brace, 2) evaluating the design and modeling of multi-story braced frames, and 3) evaluating the seismic behavior of these frames within a building. The new brace will achieve ductile and stable behavior by structurally efficient details incorporating energy-dissipating reinforcing bars crossing gap-joints at the brace ends and spliced with threaded couplers and upsized bars to minimize damage in the beam and column members. This threaded gap-joint connection will permit damaged precast braces to be replaced with cast-in-place concrete braces after an earthquake. Detailed numerical models will be developed and experimentally validated to predict three-dimensional stress gradients and damage conditions that could lead to premature failure of the brace, and to evaluate efficient design-basis models for multi-story braced frames. The modeling and design methods will be validated with the first system-level testing of a precast braced frame building on the six-degree-of-freedom shake table. These culminating tests will demonstrate the performance of the braced frames, their connections, and brace replacement under multi-directional demands.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

以前地震的损失规模表明，需要建筑物，这些建筑物可以在自然灾害后迅速恢复其基本职能。这个概念称为功能恢复。该项目将通过创建和检查具有新型非专有对角线的新型的可修复预制混凝土屈曲式支撑（BRB）框架结构来为国家的功能恢复目标做出贡献。新的支架将具有低成本的功能，可在地震后实用。该项目将对该建筑系统的地震设计和性能产生基本知识。数据将根据数值分析，孤立的支撑及其连接的测试以及对三层建筑的地震性能和修复的测试产生，该测试利用了加利福尼亚大学（San Diego），San Diego的一部分，是NSF资助的自然研究Infransontruction（NSF）的一部分，该研究是使用加利福尼亚大学（San Diego）上加利福尼亚大学（San Diego）经营的六度大型高性能的户外户外餐桌。该项目将强调多样性和包容性，将吸引人数不足的团体的教育和心理计划中的本科生，并将为前大学的学生创建工程学习模块。预制行业合作伙伴将提供标本和技术指导，强调该项目对行业偏爱的结构细节的关注，以实践接受。通过竞争，将实现与更广泛的工程社区的互动，以预测摇桌上的建筑响应。该项目生成的数据将在NHERI Data Depot（https://www.designsignsafe-ci.org）中公开归档并公开可用。该奖项将有助于NSF在国家地震危害计划（NEHRP）中的作用。目前尚无关于预制BRB框架结构的地震性能的全面研究。该项目将通过1）设计和表征新颖的，可更换的混凝土支架的行为，2）评估多层支撑框架的设计和建模，以及3）评估建筑物内这些框架的地震行为。新的支架将通过结构上有效的细节来实现延性和稳定的行为，这些细节融合了在支撑末端穿过间隙 - 关节并用螺纹耦合器和升压条剪接的隔离间隙的加固条，以最大程度地减少光束和柱子成员的损坏。这种螺纹间隙连接连接将允许损坏预制括号在地震后用现场混凝土架代替。将开发和实验验证详细的数值模型，以预测可能导致支架过早失败的三维应力梯度和损伤条件，并评估多层支撑框架的有效设计基础模型。建模和设计方法将通过对六度自由摇桌上的预制支撑框架构建的第一个系统级测试进行验证。这些最终测试将证明在多方向需求下的支撑框架，其连接和支架更换的性能。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛的影响评估的评估来通过评估来支持的。