Behaviour and retrofit of heavy timber structural systems against blast loading

重型木结构系统抗爆炸荷载的性能和改造

• 批准号: RGPIN-2018-04429
• 负责人: Doudak, Ghasan
• 金额: $ 6.27万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749462
• 关键词: Behaviour; retrofit; heavy; timber; structural

Wood is inherently light weight, flexible and brittle, which means that timber buildings are not expected to resist blast loading in a manner that adequately protects occupants against accidental and intentional explosions. In particular, protecting human lives requires prevention of progressive collapse and minimization of debris throw'. Studies by the applicant and collaborators using a unique Shock Tube Facility at the University of Ottawa has already influenced blast related design code requirements in Canada. However much more needs to be done.The overarching objective of proposed research is mitigation of hazards associated with blast loads on timber buildings. This will be achieved by establishing risk evaluation strategies and developing technically and economically viable innovative retrofit methods for new and existing buildings. The research program will generate completely new information and be the basis of HQP research training. The main focus of the experimental component of the research program will be on establishing the behaviour of heavy timber elements and devising retrofit options for existing buildings that may be vulnerable to blast events. This includes examining the effects of fibre reinforced polymers to provide confinement to the wood elements and the use of post-tensioning techniques using steel guy cable and carbon FRP bars. The analytical component will include development of nonlinear material compliance models. Once developed and verified, those models will be used for dynamic analysis and parametric studies of building structures and substructures.The proposed research program has a great potential to significantly impact the knowledge base in the field of blast design of wood structures. The output from the research will yield data that would introduce provisions to the blast design standard. Ductility ratios and support rotations for various levels of protection and values for the dynamic increase factor are important examples of potential contributions to the profession. The research program will help ensure that engineers in Canada have the best possible knowledge and information to support design decisions for wood structures. Furthering knowledge on the behaviour of timber structures under blast loads will improve safety while adding highly trained and dedicated professionals to the Canadian workforce. Importance and novelty of the proposed research is the creation of material models for wood elements, which will enable analysts to predict behaviour of timber buildings subjected to blast loading without reliance on empiricism. Intent is to enable a leap from need to rely on prescriptive method to engineering blast design practice, which is comparable to the transition which took fire design of timber buildings from an art to an applied science in the late 20th century.

木材本身重量轻，柔韧性好，易碎，这意味着木结构建筑不能承受爆炸载荷，不能充分保护居住者免受意外和故意爆炸的伤害。特别是，保护人类生命需要防止逐渐坍塌和尽量减少碎片投掷。申请人和合作者使用渥太华大学独特的激波管设备进行的研究已经影响了加拿大与爆炸相关的设计规范要求。然而，需要做的还有很多。拟议研究的总体目标是减轻与爆炸荷载对木结构建筑的危害。这将通过建立风险评估策略和开发技术上和经济上可行的创新改造方法来实现。该研究项目将产生全新的信息，并成为HQP研究培训的基础。研究计划的实验部分的主要重点将是确定重型木材元素的行为，并为可能易受爆炸事件影响的现有建筑设计改造方案。这包括检查纤维增强聚合物的效果，以限制木材元素，并使用钢拉索和碳FRP筋的后张拉技术。分析部分将包括非线性材料顺应性模型的开发。一旦开发和验证，这些模型将用于建筑结构和子结构的动态分析和参数化研究。所提出的研究方案对木结构爆破设计领域的知识库有很大的影响。这项研究的结果将为制定爆炸设计标准提供数据依据。延性比和各种保护级别的支撑旋转以及动态增加系数的值是对专业的潜在贡献的重要例子。该研究项目将有助于确保加拿大的工程师拥有最好的知识和信息，以支持木结构的设计决策。进一步了解木结构在爆炸荷载下的性能将提高安全性，同时为加拿大的劳动力增加训练有素的专业人员。所提出的研究的重要性和新颖性在于为木材元素创建材料模型，这将使分析人员能够预测木结构建筑在爆炸荷载下的行为，而不依赖于经验主义。其目的是实现从需要依赖规范方法到工程爆破设计实践的飞跃，这与20世纪后期木结构建筑的火灾设计从艺术到应用科学的转变相当。