Citation

Kordina K. Fire Safety J. 1991; 17(2): 113-128.

Copyright

(Copyright © 1991, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The method to classify structural elements with respect to the standard fire resistance tests is nowadays supplemented by a direct analytical design method, based on the natural fire concept.In some countries, research work was carried out in order to clarify the pre- and post-flashover development of natural fires, and efforts were made to obtain the possibility of comparing the effects of natural fires with those of a standard fire test (teq concept).At present, the direct analytical design procedure is limited in many countries to extraordinary structures or buildings, e.g. tunnels or industrial plants of great importance. In these cases the actual or design fire load is used within a heat and mass balance calculation, in order to determine the gas temperatures and the fire progress. Consequently, the mechanical and thermal behaviour of the structural elements surrounding the fire compartment has to be determined.In order to avoid heavy structural damage and to assure the repairability of the structure, adequate protective measures, depending on the fire exposure, have to be assessed.Examples of this kind of fire design procedure in consulting work for tunnels will be presented, which show the necessity for additional fire protective measures. A comparison between the calculated fire exposure and a full scale fire test is given, which shows good agreement between theory and experiment.