Behaviour and retrofit of heavy timber structural systems against blast loading

木头本身重量轻、柔韧、易碎，这意味着木结构建筑不能以足以保护居住者免受意外和故意爆炸的方式抵抗爆炸荷载。特别是，保护人类生命需要防止渐进性坍塌和最大限度地减少碎片抛掷。申请者和合作者使用渥太华大学独特的激波管设施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，还需要做更多的工作。拟议研究的首要目标是减轻与木结构建筑爆炸载荷相关的危险。这将通过制定风险评估战略和为新建和现有建筑物制定技术和经济上可行的创新翻新方法来实现。该研究计划将产生全新的信息，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构件的行为，并为可能容易受到爆炸事件影响的现有建筑设计翻新方案。这包括检查纤维增强聚合物对木构件提供约束的效果，以及使用钢绞线和碳纤维增强塑料筋的后张法技术的使用。分析部分将包括开发非线性材料顺应性模型。一旦开发和验证，这些模型将用于建筑结构和子结构的动力分析和参数研究。所提出的研究计划将极大地影响木结构爆破设计领域的知识库。这项研究的结果将产生数据，这些数据将为爆炸设计标准引入条款。不同级别保护的延性比和支承旋转以及动态增长系数的值是对该行业潜在贡献的重要例子。该研究计划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行为将提高安全性，同时为加拿大劳动力增加训练有素和敬业的专业人员。这项拟议研究的重要性和新颖性在于创建了木材元素的材料模型，这将使分析师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。其目的是实现从依赖于规范方法的需要到工程爆破设计实践的飞跃，这与20世纪末将木结构建筑的火灾设计从一门艺术转变为一门应用科学的过渡相媲美。

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.