NEESR-CR - Innovative Seismic Retrofits for Resilient Reinforced Concrete Buildings

该奖项是NSF 09-524项目征集“小乔治·E·布朗地震工程模拟网络(NEES)研究(NEESR)”竞赛的结果，包括佐治亚理工学院(牵头机构)、霍华德大学(次级奖项)和莱斯大学(次级奖项)。该项目将利用加州大学洛杉矶分校运营的NEES移动振动器。项目团队将评估具有重新定位和/或高阻尼能力的新型创新系统的有效性，并为其设计和实施制定框架，以改造钢筋混凝土(RC)建筑，以提高抗震性能。其目标是通过创新的大规模现场测试，验证RC建筑的一种新的翻新类别。将调查五种改造措施，包括新型支撑系统、梁柱连接元件或柱缠绕。这些系统的共同优势特征包括易于应用(几乎不需要重型机械)、可伸缩性和适应性、被动性质，以及在整个生命周期中几乎不需要维护。此外，与传统的翻新方法相比，这些系统旨在提供最低限度的损害、增强的震后功能和更高的成本效益方面的抗震性能。在创新系统中使用先进材料将改进RC建筑物的抗震改造，由于其高效的设计、最少的维护或安装中断以及更高的成本效益，可能会得到更广泛的采用。这项研究包括一系列独特的多尺度实验，加上详细的有限元模拟、脆弱性分析和成本效益研究。研究、教育和推广计划包括以下关键组成部分：(1)使用NEES移动振动器对创新的翻新系统(许多基于形状记忆合金)进行全面的系统级验证；(2)与经验丰富的设计专业人员合作，设计基于代码的翻新措施；(3)使用无线传感器的损害检测方法，投射关于创新翻新条件和系统响应的详细信息；(4)详细的易损性分析，或易损性模型，包括翻新和未翻新的建筑物；(5)成本效益和生命周期成本分析，为决策者提供关于最佳建筑改造的信息；(6)与加拿大舍布鲁克大学就缩减规模的系统级测试进行国际合作，以及在国立台湾大学和韩国弘益大学进行中等规模测试；(7)影响所有级别(K-12、大学和行业)的综合外展和教育计划；以及(8)与行业领导者一起举办的技术转让研讨会。智力优势：这项研究基于一系列多规模组件和全规模系统级现场测试，首次提供了高性能系统的大规模验证。将进行详细的分析性建模和脆弱性分析，以评估各种创新改造对减少RC建筑物的地震脆弱性的影响。将建立一个框架，从智能传感和结构损伤状态估计，到易损性建模、性能评估和改装RC建筑的成本效益研究。新系统的验证预计将通过创新的设计、材料使用和实施来改变当前建筑物抗震改造的方法，从而显著提高性能(抗震和生命周期)。更广泛的影响：拟议的研究、教育和推广计划的更广泛影响是四方面的。首先，这种新颖的多尺度测试，加上详细的分析，将首次为此类高性能系统提供已知的系统级验证。其次，拟议的翻新具有效率、成本效益和最小的破坏，可以产生更好的翻新方法，并得到广泛应用，以提高全国的建筑性能。第三，与行业合作伙伴的协作和在实际结构中进行改造的实地测试将解决实施方面的现实挑战，并简化向实践的转移。一系列研讨会将汇集学者、研究人员和工业界，以推动抗震建筑改造创新系统的转移。第四，一个多方面的教育计划解决了改善高中科学和工程课程的需要，同时解决了缺乏在STEM(科学、技术、工程和数学)领域获得学位的代表人数不足的学生的问题。该项目的数据将通过NEES数据库存档并向公众提供。该奖项是国家减少地震灾害计划(NEHRP)的一部分。

This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the Georgia Institute of Technology (lead institution), Howard University (subaward), and Rice University (subaward). The project will utilize the NEES mobile shakers operated by the University of California, Los Angeles.The project team will evaluate the efficacy of a new class of innovative systems with recentering and/or high damping capabilities, and develop a framework for their design and implementation to retrofit reinforced concrete (RC) buildings to improve seismic performance. The goal is to validate, via innovative large scale field testing, a new class of retrofits for RC buildings. Five retrofit measures will be investigated, consisting of novel bracing systems, beam-column connection elements, or columns wraps. Common advantageous characteristics of the systems include the ease of application (requiring little-to-no heavy machinery), scalability and adaptability, passive nature, and need for little-to-no maintenance through the life-cycle. Furthermore, these systems aim to provide improved seismic performance in terms of minimal damage, enhanced post-event functionality, and improved cost-benefit compared to traditional retrofit approaches. The use of advanced materials in innovative systems will result in improved seismic retrofits for RC buildings that may find more widespread adoption due to their efficient design, minimal maintenance or disruption for installation, and enhanced cost-effectiveness. The research includes a series of unique multi-scale experiments, coupled with detailed finite element simulations, fragility analyses, and cost-benefit studies. Research, education, and outreach plans include the following key components: (1) first of its kind full-scale system-level validation of innovative retrofit systems (many based on shape memory alloys) using the NEES mobile shakers; (2) code-based designs of retrofit measures, in collaboration with experienced design professionals; (3) damage detection approaches using wireless sensors that project detailed information on the condition of the innovative retrofits, and the system response; (4) detailed fragility analyses, or vulnerability models, of buildings with and without retrofit; (5) cost-benefit and life-cycle cost analyses to inform decision-makers on optimal building retrofits; (6) international cooperation on reduced-scale system-level tests with Sherbrooke University in Canada, and medium-scale testing at National Taiwan University, and Hongik University (Korea); (7) a comprehensive outreach and education program impacting all levels (K-12, college, and industry); and (8) workshops focused on technology transfer with industry leaders.Intellectual Merit: This research provides the first large-scale validation of high performance systems based on a series of multi-scale component and full-scale system-level field tests. Detailed analytical modeling and fragility analyses will be performed to assess the impact of various innovative retrofits on reducing the seismic vulnerability of RC buildings. A framework will be established, ranging from smart sensing and structural damage state estimation, to fragility modeling, performance assessment, and cost-benefit studies of retrofitted RC buildings. The validation of the new systems are expected to provide a marked advance in performance (seismic and life-cycle) through innovative design, material usage, and implementation to transform current approaches for seismic retrofit of buildings.Broader Impacts: The broader impacts of the proposed research, education, and outreach program are four-fold. First, the novel multi-scale testing, coupled with detailed analysis, will provide the first known system-level validation of such high performance systems. Second, the efficiency, cost-effectiveness, and minimal disruption caused by retrofits proposed can result in superior retrofit approaches with broad application to improve building performance nationwide. Third, the collaboration with industry partners and field testing of retrofits in real structures will address realistic challenges of implementation and streamline transfer to practice. A series of workshops will bring together academics, researchers, and industry to advance the transfer of innovative systems for seismic building retrofit. Fourth, a multi-faceted education program addresses the need to improve high school science and engineering curriculum, while addressing the lack of underrepresented students pursuing degrees in the STEM (science, technology, engineering, and mathematics) arena.Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).