Fire-Exposed Reinforced Concrete Frames: Structural Performance, Progressive Collapse Assessment and Retrofit Strategy

暴露在火灾中的钢筋混凝土框架：结构性能、渐进式倒塌评估和改造策略

• 批准号: RGPIN-2015-06058
• 负责人: Youssef, Maged
• 金额: $ 1.6万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=678689
• 关键词: Fire; Exposed; Reinforced; Concrete; Frames

The collapse of the towers of the World Trade Center and the many documented fire-initiated structural failures raise grave concerns about public safety. The majority of Reinforced Concrete (RC) structures are designed using prescriptive fire design approaches that are based on structural tests of RC elements exposed to standard fires. However, they possess significant drawbacks including: undefined safety margin at the structure level, unknown resistance to progressive collapse and inapplicability to consider innovative cost-saving solutions demanded by the complex natural fire phenomena. They also fail to provide the needed guidance to evaluate and retrofit fire-damaged structures.***Design standards are being revolutionized by specifying acceptable performance criteria or design objectives to allow for engineering innovations. This revolution is causing a major shift in the balance of responsibility for fire safety between the architect and the structural engineer who needs to develop the necessary expertise and be equipped with the right analytical tools. These tools should expedite the design process allowing for the justification of the benefits associated with the additional engineering work.***The Applicant's research group has recently developed and validated simplified methods and tools to analyze and design RC frames exposed to standard fire. These provide researchers and engineers with the necessary means to understand the complicated structural behaviour under fire exposure, to design RC frames to satisfy specific safety objectives and to validate analysis results from commercial computer programs.***The proposed research will further develop the Applicant's methods and tools to make them suitable for cases of natural fire. Their use will allow for performance-based design of new structures and provide means to assess the safety of fire-damaged structures considering the potential of progressive collapse. Such assessment is essential to make critical decisions about the need for evacuation prior to retrofitting. Emergency response teams are in desperate need of such tools to continuously monitor the condition of fire-exposed structures to guarantee the safety of their personnel. The research will also provide tools to design retrofitting techniques for fire-damaged RC frames that guarantee public safety.***The proposed research will utilize the unique fire facility at Lambton College's Fire & Public Safety Centre of Excellence to expose RC elements to fire before testing them at Western's Structures Lab. Test results will lead to the development and validation of the above-mentioned tools. 6 HQPs and 25 Undergraduate students will experience unique testing procedures involving interaction with technicians from Western and Lambton, and will develop analytical skills that are much needed within the structural engineering profession in Canada and worldwide.**

世贸中心双子塔的倒塌和许多有记录的火灾引发的结构故障引发了人们对公共安全的严重担忧。大多数钢筋混凝土(RC)结构的设计采用规范的火灾设计方法，这些方法基于暴露在标准火灾下的RC构件的结构试验。然而，这些方法都有明显的缺陷，包括：结构层面的安全裕度不明确，对连续倒塌的抗力未知，以及不能考虑复杂的自然火灾现象所要求的创新的节约成本的解决方案。它们也没有提供必要的指导，以评估和改造火灾损坏的结构。*设计标准正在发生革命性的变化，规定了可接受的性能标准或设计目标，以允许工程创新。这场革命导致建筑师和结构工程师之间的消防安全责任平衡发生了重大变化，结构工程师需要发展必要的专业知识并配备正确的分析工具。这些工具应该加快设计过程，从而证明与额外工程工作相关的好处是合理的。*申请人的研究小组最近开发并验证了简化的方法和工具，以分析和设计暴露在标准火灾下的RC框架。这些研究为研究人员和工程师提供了必要的手段，以了解火灾下复杂的结构行为，设计RC框架以满足特定的安全目标，并验证商业计算机程序的分析结果。*拟议的研究将进一步发展申请人的方法和工具，使其适用于自然火灾的情况。它们的使用将允许新结构的基于性能的设计，并提供考虑到逐步倒塌的可能性来评估被火灾损坏的结构的安全性的手段。这种评估对于在翻新之前就疏散的必要性作出关键决定至关重要。应急小组迫切需要这样的工具来持续监测火灾建筑物的状况，以确保其人员的安全。这项研究还将提供工具，为被火灾损坏的钢筋混凝土框架设计翻新技术，以保证公共安全。*拟议的研究将利用兰布顿学院消防与公共安全卓越中心的独特消防设施，将钢筋混凝土构件暴露在火灾中，然后在韦斯特的结构实验室进行测试。测试结果将导致开发和验证上述工具。6名HQP和25名本科生将体验独特的测试程序，包括与来自西方和兰布顿的技术人员的互动，并将培养加拿大和世界各地结构工程专业非常需要的分析技能。