A segregated structure is a unit comprising smaller, distinct ‘compartments’ or ‘volumes’ which are separated by various ‘barriers’. If a fire starts in one of these volumes it may spread to other volumes in the structure by breaching the interposed barriers. A general model to assess the risk from fire spreading through a structure in which one or more volumes is in some sense critical is introduced. The model is time-dependent, based upon failure-time probability distributions assigned to each barrier and embracing extreme value theory in the determination of the probability distribution of the time taken for a fire to reach a particular critical volume.

Time-dependent stochastic modelling of fire spread in segregated structures

Fire risk in linear segregated structures—fire door determination

A segregated structure is regarded as a collection of volumes joined together by barriers. A fire, starting in one of the volumes, may spread through its bounding barriers to other volumes. The safety assessment of a vital piece of equipment contained in a particular volume, or passing through several volumes, needs to contain a contribution associated with the risk of damage by fire which starts in or spreads to these crucial volumes. A technique is described for doing this using the directed graph of a reduced network with ‘fire transition’ probabilities assigned to its arcs. This time-independent approach has been implemented in a computer program. Examples illustrating its use are given. Extensions which include the temporal aspect, and involve the stochastic modelling of the time taken for a fire to breach a barrier, are discussed.

A. Veevers

Papers

Probabilistic Risk Assessment Associated with Fire Spread in Segregated Structures