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

迫切需要用可持续、低碳足迹材料建造的低成本、多危险、有弹性的建筑。由薄壁冷弯型钢(CFS)构成的中层建筑有能力满足这一迫切需求。CFS框架结构的潜在好处包括低安装和维护成本、高耐久性和延性、轻质框架以及使用回收材料的制造工艺。此外，与其他轻质框架解决方案相比，材料性能的一致性、高强度重量比和刚度以及使用不可燃材料都具有额外的优势。通过使用框架方案，将密集的垂直构件重复放置在墙壁中，CFS建筑通过连接到这些垂直构件上的带子、板材或护套来发展侧向阻力。这些建筑系统在地震荷载下的反应，特别是设计工程师没有特别指定的建筑系统部分对抗震荷载的贡献还没有得到很好的了解。该奖项将进行一系列实验和补充的数值模拟，以表征指定的侧向力抵抗系统(即剪力墙)与整个CFS建筑系统响应之间的关系，包括在地震事件中重力墙、饰面材料和内部隔断的影响。总体而言，该项目将通过促进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。研究团队将对不同的初高中学生和教师群体进行教育和推广，并将高中、本科生和研究生研究人员纳入项目活动，以帮助培训下一代劳动力。由于重复框架结构具有较大的超强度和非指定体系在横向反应中的显著贡献，其抗震性能是独一无二的。在这个项目中，将进行一系列将建筑物拆解为墙线和独立组件的实验，以提供独特的信息，以了解基准全尺寸振动台测试。振动台测试将在加州大学圣迭戈分校由NSF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，非线性的所有主要成分将第一次被捕捉到互补的数字建筑模型中，当得到验证时，这些模型将成为更广泛的地震研究和评估的基础。项目数据将在位于https://www.designsafe-ci.org/.的NHERI数据仓库中提供

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/.