Application of Quantified Risk Assessment to the Building Fire Safety Problem

Traditionally building fire safety has been achieved through compliance with prescriptive building regulations. However, legislation is intended to ensure that minimum life safety levels are achieved, it is not intended to form the basis for design. In recognition of the limitations of this approach, the UK Building Regulations were revised in 1985 to make them more flexible and to accommodate the fire safety engineering approach to design.
This thesis describes the development and application of a methodology for the quantification of fire risks in buildings. The methodology represents an adaptation of the classical framework for quantified risk assessment that has proven to be successful in other fields of engineering. Fire safety engineering knowledge and techniques are integrated with a formalised method of safety analysis to produce a tool which can be used as an aid for decision-making. In its present form, it is considered to be a compliment to, rather than a replacement for, existing methods.
The methodology adopts a hybrid probabilistic/deterministic modelling approach, utilising existing techniques and calculation methods. Separate calculation models have been developed for the quantification of life and property risks. A qualitative framework is described for rationalizing the building fire safety system and focusing on the quantitative analysis, particularly for the life risk analysis. The property risk analysis utilises a Monte Carlo simulation technique to model fire spread through the building. Property loss is related to the area of fire damage.
The methodology is structured so that it can accommodate new or improved knowledge as and when it becomes available. As the methodology is further developed and the level of sophistication and comprehensiveness increases, it should ultimately be possible to use it for the demonstration of code equivalency.
In its present form, the methodology has been applied to investigate the risk to life and property in a simple office building and it has been shown that the results can be used as a basis for deciding between alternative fire safety strategies. A sensitivity analysis has been undertaken to determine the effect of variations in the input parameters on the results.