Consequences of using Quantitative Risk Assessment as a verification tool

Abstract: What are the consequences of using Quantitative risk assessment (QRA) as a verification tool? Performance-based building codes differ from prescriptive-based codes in that they define specific objectives to be met, enabling the building designer to choose which solution to use so long it meets the objectives. This master’s thesis explores the consequences of using QRA as a verification tool in comparison to existing verification methods currently in use in Australia. The thesis consists of a literature study examining currently existing quantitative risk-based methods, and a case study to test and illustrate the application of the proposed Part A8 of The Building Code of Australia (BCA) 2022, which contains quantitative risk criteria, followed by evaluation and analysis of the results. The study was limited to an already existing residential building with suggested fire safety measures. An event tree based QRA approach was used to quantify the individual and societal risk for the building. The results show that the already existing building meets most of the risk-based criteria of the proposed legislation. Improving the reliability of certain fire protection systems is shown to reduce the risk level for the building. The use of QRA to verify fire safety is expected to lead to a more holistic fire safety design and may lead to a more robust fire safety design. However, there are several challenges related to the use of QRA to verify fire safety in buildings.