Resiliency Framework for Seismic Risk Assessment and Management of Buildings

加拿大保险局（IBC）估计，地震对西部（不列颠哥伦比亚省）和东部（渥太华-蒙特利尔-魁北克城市走廊）核心公共基础设施（CPI）造成的损失约为600 - 750亿美元。国际生物伦理委员会的报告进一步强调，通过纳入复原力，可以大大减少损害。系统的地震弹性与减少地震发生的机会、吸收地震并在地震后迅速恢复有关。CPI，包括道路、桥梁、交通、供水和废水系统，对确保加拿大的健康、安全、经济保障和整体生活质量至关重要。这项研究计划的长期目标是为加拿大的CPI制定一个弹性框架。该框架将纳入每个CPI的故障以及依赖关系和级联效应。此外，该框架将包括多次地震，例如主震-余震地震。 在本提案中，弹性框架适用于不同的加拿大建筑类型，重点是减少地震的影响，并通过量化市中心的失败后果来改善恢复。为了实现这一目标，研究目标分为以下三个主题： 主题A）通过考虑不同的不确定性和建筑物不规则性，为现有建筑物制定建筑物脆弱性评估和坚固性指数框架（项目A1和A2）。根据现有的信息水平，将制定一个建筑物脆弱性评估准则，其中包括模型选择和分析技术。最后，将制定一项新的《加拿大建筑规范有效性分级议定书》，并将其适用于600多个加拿大城市（如建筑规范所规定）。 主题B）制定综合的改造优化和选择框架。这一框架将使决策者能够对不同的改造备选方案进行情景分析，并选择所需的改造技术（项目B1、B2和B3）。改造资源的分配和优化将在两个不同的解决方案（城市和建筑物一级）进行，并涉及不同危害程度的模拟。在这项研究中，将使用一个无导数的方法，保证最优性。由于与危害评估有关的不确定性和对具体替代品决策过程的了解，决策方面的挑战进一步复杂化。 主题C）制定一个框架，在风险评估和管理框架内量化结构性和非结构性故障。该框架将通过故障树说明故障的可能性，并通过事件树分析说明故障的后果。这在风险文献中被表示为蝴蝶结图。因此，主题A中的建筑物脆弱性工具和主题B中的改造评估框架将被集成到这个蝴蝶结图中。停机时间将被量化为解决弹性框架（项目C1）的快速恢复组件的故障的后果之一。 这项研究将导致对地震风险评估的深入了解，并显着改善民用基础设施系统的管理。从这一重要研究中获得的知识和理解将直接改善现有建筑物的风险评估和管理。这将通过提高我国民用基础设施系统的弹性，对加拿大社会产生重大影响。

The Insurance Bureau of Canada (IBC) estimation of earthquake induced damage to core public infrastructure (CPI) in western (British Columbia) and eastern (Ottawa-Montreal-Quebec City corridor) is in the order of $60-$75 billion. The IBC’s report further highlighted that with the incorporation of resiliency, the damage can significantly be reduced. Seismic resiliency of a system has been associated with reducing chances, absorbing and recovering quickly after a shock. CPI, including roads, bridges, transit, and water and wastewater systems, are essential to ensure health, safety, economic security and overall quality of life in Canada. The long term objective of this research program is to develop a resiliency framework for Canada’s CPI. The framework will incorporate the failure of each CPI and also dependencies and cascading effects. Furthermore, the framework will incorporate multiple shocks, e.g. mainshock-aftershock earthquakes. In this proposal, the resiliency framework is applied for different Canadian building types, with focus on reducing impact of an earthquake and improving the recovery by quantifying the downtown in the consequence of failure. To achieve this objective, the research goals are categorized into the following three themes: Theme A) Develop building vulnerability assessment and robustness index framework for existing buildings by accounting for different uncertainties and building irregularities (Projects A1 and A2). Based on the level of information available a building vulnerability assessment guidelines that incorporate model selection and analysis technique will be developed. Finally, a new Canadian Building Code Effectiveness Grading protocol will be developed and applied to over 600 Canadian cities (as provided in the building code). Theme B) Develop an integrated retrofit optimization and selection framework. This framework will enable the decision makers to carry out scenario analysis for different retrofit alternatives and select the desired retrofitting technique (projects B1, B2 and B3). The retrofit resource allocation and optimization will be undertaken at two different resolutions (city and building levels) and involve simulations for different hazard levels. In this research, a derivative-free approach that guarantee of optimality will be used. The challenge of decision making is further compounded due to the uncertainties associated with hazard assessment and knowledge of the decision making process for specific alternatives. Theme C) Develop a framework that will quantify both structural and non-structural failures within the risk assessment and management framework. This framework will account for the likelihood of failure through fault-tree and consequence of failure through event-tree analyses. This is denoted as a bow-tie diagram in the risk literature. Thus, the building vulnerability tool from Theme A and retrofitting assessment framework from Theme B will be integrated into this bow-tie diagram. Downtime will be quantified as one of the consequence of failure that addresses the recover quickly component of the resiliency framework (project C1). This research will lead to an advanced understanding of seismic risk assessment and significantly better management of civil infrastructure systems. The knowledge and understanding gained from this critical research will directly improve the risk assessment and management of existing buildings. This will have significant impact on Canadian society by improving the resiliency of our civil infrastructure systems.