Development of Design Guidelines for Steel Cantilever Beams in Canada

加拿大钢悬臂梁设计指南的制定

• 批准号: 543526-2019
• 负责人: Imanpour, Ali
• 金额: $ 2.57万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=699099
• 关键词: Development; Design; Guidelines; Steel; Cantilever

The roofs of many light single-storey steel buildings in North America that are large in plan area, such as supermarkets or big box stores, are built using the "Gerber system" to resist gravity loads. The Gerber system consists of cantilever girders that are supported atop the columns and interstitial drop-in girder segments along the column line in one direction, typically with open-web steel joists constituting the secondary framing in the perpendicular direction. This system tends to reduce girder sizes by taking advantage of the negative moment capacity of the girders at the column supports, while maintaining a cost similar to that of a simply-supported frame structure. The design of girders in such systems is often governed by their stability. The current Canadian standard for design of steel buildings, CSA S16, provides very limited information related to the Gerber system and it is therefore the responsibility of the structural engineer to develop a rational design method. Remarkably, and of concern to several leading industry experts, widely-used textbooks and guidelines may not adequately describe the behaviour and resistance of such system. This research project aims to develop design methods for steel Gerber systems and has four specific objectives: 1) to identify the influential parameters pertaining to the stability of cantilever girders; 2) to assess, by means of numerical simulations and a full-scale experimental program, the stability response of such girders; 3) to develop design methods for Gerber systems and other cantilevers, and propose stability design requirements within the framework of the Canadian steel design standard; and 4) to perform a thorough reliability analysis. The research team will perform full-scale laboratory experiments and employ advanced numerical modelling techniques to achieve the objectives of this project. The results will provide improved design tools to structural engineers for use in day-to-day practice, resulting in safer structures while reducing construction costs. The data obtained from the experimental test program proposed here will supplement existing studies to instill greater confidence in the validity of the design equations prescribed for cantilever girders.

北美许多平面面积较大的轻型单层钢结构建筑，如超市或大型卖场，其屋顶均采用“格柏系统”来抵抗重力荷载。 Gerber 系统由支撑在柱顶的悬臂梁和沿着柱线在一个方向上的间隙插入式梁段组成，通常使用开放腹板钢托梁构成垂直方向的二级框架。该系统倾向于通过利用柱支撑处大梁的负力矩能力来减小大梁尺寸，同时保持与简支框架结构相似的成本。此类系统中梁的设计通常取决于其稳定性。 目前加拿大钢结构建筑设计标准 CSA S16 提供的与 Gerber 系统相关的信息非常有限，因此结构工程师有责任开发合理的设计方法。值得注意的是，广泛使用的教科书和指南可能无法充分描述此类系统的行为和阻力，这引起了一些领先行业专家的关注。该研究项目旨在开发钢格伯系统的设计方法，有四个具体目标：1）确定与悬臂梁稳定性相关的影响参数； 2）通过数值模拟和全尺寸实验程序评估此类梁的稳定性响应； 3）开发Gerber系统和其他悬臂的设计方法，并在加拿大钢结构设计标准的框架内提出稳定性设计要求； 4) 进行彻底的可靠性分析。研究团队将进行全面的实验室实验并采用先进的数值建模技术来实现该项目的目标。研究结果将为结构工程师提供改进的设计工具，供其在日常实践中使用，从而使结构更安全，同时降低施工成本。从此处提出的实验测试计划中获得的数据将补充现有研究，以增强对悬臂梁设计方程有效性的信心。