GOALI: Development of a Seismic Design Methodology for Precast Floor Diaphragms

预制楼板隔板抗震设计方法的开发- CMS 0324522 PI：Robert Fleischmann，亚利桑那州由亚利桑那大学（UA）、加州圣地亚哥大学（UCSD）和利哈伊大学（LU）组成的财团与预制/预应力混凝土研究所（PCI）一起提出了一个合作研究项目，以开发一个全面、准确、以及地震荷载下建筑物中预制混凝土楼板隔板的有效设计方法。对于这种合作，大学带来了地震荷载下预制楼板横隔的关键问题的知识，以及所需的分析和实验专业知识和设施。 PCI代表全国预制混凝土行业，带来了行业实践，标准和经济学的知识，以及项目共同资助。 通过使用紧密集成的实验和分析模拟，该项目将大大提高对预制楼板横隔梁抗震性能的认识，并开发有关关键预制横隔梁元件的刚度、强度和延性能力的信息。将这些结果与行业知识相结合，该项目将产生适当的抗震设计方法。 该项目是作为一个产学合作项目提交给NSF的学术联络与工业（GOALI）计划的资助机会。为预制混凝土楼板隔板开发适当的抗震设计方法是具有挑战性的，并且解决了几个关键问题：（1）隔板中产生的地震力水平取决于隔板和主要侧向力抵抗元件（例如，剪力墙和抗弯框架）;（2）动力相互作用取决于横隔梁和侧向力系统的弹性和非弹性特性;（3）由于第（1）和（2）项的结果，很难对横隔梁的设计力作出简单、准确的估计;（4）预制横隔梁的非弹性行为，包括内力抵抗机制、关键元件的变形要求和能力，由于这些横隔梁的接合性质，是复杂的且知之甚少;（5）需要将横隔锚定到抗侧向力元件的细节;以及（6）需要精确的方法来估计由于预制楼板横隔的柔性而对建筑物的抗重力系统的侧向偏移需求。为了解决这些问题，该联盟的研究将整合以下内容：（1）通过应用简单的循环力模式和历史，以及复杂的循环力模式和历史，（多自由度）力的模式和历史;（2）完整楼板的详细有限元（FE）分析（在地震荷载下）确定将用于实验和开发隔板设计要求的隔板元件的临界力模式和历史;（3）原型建筑的非线性时程动力分析（NTDA），以确定隔板地震力水平;（4）整个结构的准静态隔板试验和振动台试验，以验证FE和NTDA结果，并为关键隔板元件的大规模试验提供额外的输入;和（5）预制施工方法和经济学、设计实践和设计规范开发问题的行业知识。智力优势。 该项目将开发新的知识的动态之间的相互作用的地板隔板和主要的横向力抵抗元件的条件下，隔板的灵活性是不可忽略的，隔板的非弹性行为是可能的。该项目还将开发有关预制横隔梁非弹性行为的新知识，由于预制系统的接缝性质以及接缝处钢筋的柔性和有限变形能力，这是复杂的。为了实现这些目标，该项目将推进大规模实验模拟与分析模拟集成的最新技术，这种集成将在各机构之间完成，UA提供分析模拟以推动LU和UCSD的实验。更广泛的影响。 该项目将直接影响预制混凝土建筑的抗震设计实践和规范。 行业参与者和顾问的数量以及PCI对该项目的财政捐款（426 000美元）证明了行业的兴趣。 该项目的结果，当部署，将导致安全和经济的预制隔膜设计。 此外，该项目将支持4名研究生，他们将通过研究和与行业从业者的互动来接受教育。 研究成果将用于参与大学的研究生课程和行业从业人员的短期课程。

Development of a Seismic Design Methodology for Precast Floor Diaphragms -- CMS 0324522PI: Robert Fleischmann, ArizonaA consortium comprised of the University of Arizona (UA), the University of California San Diego (UCSD), and Lehigh University (LU), together with the Precast/Prestressed Concrete Institute (PCI) proposes a collaborative research project to develop a comprehensive, accurate, and efficient design methodology for precast concrete floor diaphragms in buildings under seismic loading. To this collaboration, the universities bring knowledge of critical issues for precast floor diaphragms under seismic loads, as well as the required analytical and experimental expertise and facilities. PCI, which represents the precast concrete industry nationwide, brings knowledge of industry practices, standards, and economics, as well as project co-funding. Using closely integrated experimental and analytical simulations, the project will significantly advance knowledge of the seismic behavior of precast floor diaphragms and develop information on the stiffness, strength, and ductility capacity of critical precast diaphragm elements. Integrating these results with industry knowledge, the project will produce an appropriate seismic design methodology. The project is proposed to the NSF.s Grant Opportunities for Academic Liaison with Industry (GOALI) program as an Industry-University Collaborative Project. The development of an appropriate seismic design methodology for precast concrete floor diaphragms is challenging and addresses several critical issues: (1) the seismic force levels developed in diaphragms depend on dynamic interaction between the diaphragms and the primary lateral force-resisting elements (e.g., shear walls and moment resisting frames); (2) the dynamic interaction depends on the elastic and inelastic behavior of both the diaphragms and the lateral force systems; (3) as a result of items (1) and (2), simple, accurate estimates of design forces for diaphragms are difficult to make; (4) the inelastic behavior of precast diaphragms, including the internal force-resisting mechanisms, and the deformation demands and capacities of critical elements, is complex and poorly understood because of the jointed nature of these diaphragms; (5) details to anchor the diaphragms to the lateral force-resisting elements are needed; and (6) accurate methods to estimate the lateral drift demands on the building's gravity-force resisting systems due to the flexibility of precast floor diaphragms are needed. To address these issues, the consortium's research will integrate the following: (1) large-scale experiments to determine the flexibility, strength, and ductility of critical diaphragm elements by applying both simple cyclic force patterns and histories, and complex (multi-degree-of-freedom) force patterns and histories; (2) detailed finite element (FE) analyses of complete floor diaphragms (under seismic load) to determine critical force patterns and histories for diaphragm elements that will be applied in the experiments and used in developing diaphragm design requirements; (3) nonlinear time-history dynamic analyses (NTDA) of prototype buildings to determine diaphragm seismic force levels; (4) quasi-static diaphragm tests and shaking table tests of entire structures to verify the FE and NTDA results and provide added input into the large-scale experiments on critical diaphragm elements; and (5) industry knowledge of precast construction methods and economics, design practices, and design code development issues. Intellectual Merit. The project will develop new knowledge of the dynamic interactions between floor diaphragms and the primary lateral force-resisting elements under the conditions where the diaphragm flexibility is not negligible and inelastic behavior of the diaphragm is likely. The project will also develop new knowledge of the inelastic behavior of precast diaphragms, which is complex owing to the jointed nature of the precast system and the flexibility and limited deformation capacity of the reinforcement across the joints. To accomplish these goals, the project will advance the state-of-the-art in integrating large-scale experimental simulations with analytical simulations, and this integration will be accomplished across institutions, with UA providing the analytical simulations to drive experiments at LU and UCSD. Broader Impact. The project will directly impact seismic design practice and codes for precast concrete buildings. The interest of industry is evidenced by the number of industry participants and advisors, and PCI's financial contributions ($426,000) to the project. The project results, when deployed, will result in safe and economical precast diaphragm designs. In addition, the project will support 4 graduate students, who will be educated by the research and the interactions with industry practitioners. The research results will be utilized in graduate curriculum at the participating universities and in short courses for industry practitioners.