PUBLICATIONS AND VIDEOS

SUMMARY

Structural fire engineering is one of the most important concepts in the provision of overall fire safety. It is widely regarded as a passive measure i.e. something that helps a structure withstand a severe fire, rather than an active measure which warns of, or intervenes to reduce the effects of a fire. As a fire develops, the structural elements affected by the fire will start to get hot; there are two consequences to this. First, the structural material will start to expand and depending on how structural elements are supported, this manifests itself as an increase in deflection and/or thermally induced forces and moments where a member’s expansion is restrained. Secondly, the structural material properties start to degrade as the temperature of the structural elements increase. The rate at which these two effects contribute to the performance of the structure depends on the rate at which the structure heats up.

A range of approaches can be used to ensure satisfactory structural performance during fire. These vary from simple prescription e.g. the required thickness of applied fire protection for steelwork, or the cover to reinforcement in concrete, to more complex analytical calculations. Irrespective of the type of approach, a three-step procedure is usually followed: (1) determination of an appropriate fire exposure to apply to the structure; (2) determination of the thermal response of the structure; and (3) determination of the structural response.

This webinar describes the principles of structural fire engineering and the three-step procedure noted above. These procedures are illustrated using a number of simple examples. Whilst reference is made in some instances to the Eurocode for fire design of steel structure (EN 1993-1-2), the principles presented are generic and widely applicable.