Collaborative Research: Seismic Resiliency of Repetitively Framed Mid-Rise Cold-Formed Steel Buildings

迫切需要用可持续的低碳足迹材料建造低成本、多灾害抵御能力强的建筑。由薄壁冷弯型钢（CFS）框架的中层建筑有能力满足这一迫切需求。碳纤维框架结构的潜在优势包括安装和维护成本低、耐久性和延展性高、框架重量轻，以及使用回收材料的制造过程。此外，与其他轻量化框架解决方案相比，材料性能的一致性、高强度重量比和刚度以及不燃材料的使用都具有额外的优势。通过使用紧密间隔的垂直构件重复放置在墙壁上的框架方案，CFS建筑通过连接到这些垂直构件的带、板或护套来发展横向阻力。这些建筑系统在地震荷载作用下的反应，特别是设计工程师没有特别指定抵抗地震荷载的部分建筑系统的贡献，还没有得到很好的理解。该合同将进行一系列实验和互补的数值模拟，以表征指定的抗侧力系统（即剪力墙）与完整的CFS建筑系统响应之间的关系，包括重力墙、饰面材料和内部隔墙在地震事件中的影响。总的来说，该项目将通过提高对易受极端自然灾害影响的CFS建筑系统的基本理解和设计方法，为国家的福利做出贡献。该研究计划涉及加州大学圣地亚哥分校（UCSD）、约翰霍普金斯大学和相关行业组织之间的综合合作。研究小组将对不同群体的初高中学生和教师进行教育和推广，并将高中、本科生和研究生研究人员纳入项目活动，以帮助培养下一代劳动力。重复框架结构的抗震性能是独特的，因为它具有较大的超强度和非指定系统在横向反应中的重要贡献。在这个项目中，将进行一组实验，将建筑物分解为墙线和单独的组件，为理解基准全尺寸振动台测试提供独特的信息。振动台试验将在加州大学圣地亚哥分校由美国国家科学基金会支持的自然灾害工程研究基础设施（NHERI）大型高性能室外振动台上进行。利用这些实验，非线性的所有主要组成部分将首次被捕获到互补的数值建筑模型中，当这些模型得到验证时，将成为更广泛的地震研究和评估的基础。项目数据将在NHERI数据仓库中提供，网址为https://www.designsafe-ci.org/。

The need for low cost, multi-hazard resilient buildings constructed of sustainable, low-carbon footprint materials is urgent. Mid-rise buildings framed from thin-walled, cold-formed steel (CFS) have the ability to support this urgent need. The potential benefits of CFS-framed structures include low installation and maintenance costs, high durability and ductility, lightweight framing, and a manufacturing process using recycled material. In addition, consistency in material behavior, high strength-to-weight ratio and stiffness, and use of a non-combustibile material are added benefits compared with other lightweight framing solutions. By using framing schemes with closely-spaced vertical members repetitively placed in the walls, CFS buildings develop lateral resistance through strap, sheet, or sheathing attached to these vertical members. The response of these building systems under earthquake loads and, in particular, the contribution of portions of the building system not specifically designated by the design engineers to resist earthquake loads are not well understood. This award will undertake a series of experiments and complementary numerical modeling to characterize the relationship between the designated lateral force resisting system, i.e., the shear walls, and the complete CFS building system response, including the impact of the gravity walls, finish materials, and interior partitions, during seismic events. Taken in totality, this project will contribute to the nation's welfare by advancing fundamental understanding and design methodologies for CFS building systems vulnerable to extreme natural hazards. The research plan involves an integrated collaboration among the University of California, San Diego (UCSD), Johns Hopkins University, and relevant industry organizations. The research team will conduct education and outreach to a diverse group of middle and high school students and teachers and integrate, into the project activities, high school, undergraduate, and graduate student researchers to help train the next generation workforce. The seismic resistance of repetitively framed structures is unique due to the large overstrength and the significant contribution of non-designated systems in the lateral response. In this project, a set of experiments de-constructing the building into wall lines and separate components will be conducted to provide unique information in understanding benchmark full-scale shake table tests. The shake table tests will be conducted on the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) Large High Performance Outdoor Shake Table at UCSD. Using these experiments, for the first time, all major components of nonlinearity will be captured in complementary numerical building models that, when validated, will form the basis for wider seismic studies and evaluation. Project data will be made available in the NHERI Data Depot at https://www.designsafe-ci.org/.