Maximum allowable damage approach to fire safety performance quantification

Risk assessments are used to inform decision-making in hazardous systems. The process involves highly technical steps such as quantifying uncertainty and it is typically carried out by subject matter experts with a robust engineering background. The process also involves value-loaded steps such selecting the risk acceptance criteria for evaluating the risks. In the built environment, risk assessments support performance-based design and of late, these have been increasingly framed as the preferred option to quantify and demonstrate adequate fire safety performance. This argument is supported by the assumption that risk is an adequate proxy for fire safety goals. The present work puts forward a counterargument, stating that fire safety performance should be mainly defined as a function of fire consequences, avoiding the use of fire risk assessments as a proxy to fire safety goals. An alternative fire risk assessment methodology is introduced based on the concept of maximum allowable damage, which is exemplified in a combustible façade residential building case-study. The methodology presented here aims at building upon the knowledge and tools of fire safety engineering to obtain more trustworthy risk assessments and therefore attain a safer built environment.

风险评估用于为危险系统中的决策提供信息。该过程涉及高度技术性的步骤，例如量化不确定性，并且通常由具有扎实工程背景的主题专家进行。该过程还涉及一些包含价值判断的步骤，比如选择风险接受标准来评估风险。在建筑环境中，风险评估支持基于性能的设计，并且最近，这些评估越来越多地被视为量化和证明足够消防安全性能的首选方案。这一论点基于风险是消防安全目标的适当替代指标这一假设。本研究提出了一个相反的论点，指出消防安全性能应主要定义为火灾后果的函数，避免使用火灾风险评估作为消防安全目标的替代指标。基于最大允许损害的概念引入了一种替代的火灾风险评估方法，并在一个可燃外立面住宅建筑案例研究中进行了示例说明。这里介绍的方法旨在基于消防安全工程的知识和工具，以获得更可靠的风险评估，从而实现更安全的建筑环境。