Samchenko T. Research of fire resistance of enclosing constructions of cable tunnels in the conditions of real fires

The problem of fire safety of electric cables became more acute in the 70-ies of the last century due to the growing number of fires at thermal power plants and nuclear power plants (NPPs) as well as other large power facilities. This increase in number of fires in cable communications is largely due to increase in the number of cables used for power supply, monitoring and control of electrical equipment in up-to-date industries as well as in the process of soil laying of industrial cables without additional measures for their fire protection. Branched cable communications are not only carriers of fire load, but also directional systems by which fire can spread across buildings and structures. Cable products are constantly evolving and improving. To conduct tests for fire resistance of building structures of cable tunnels a standard time-temperature fire curve is realized which may not correspond to the fire regime in a real cable tunnel. The study of the temperature regime of fire is an actual topical issue as cable tunnels differ in geometric configuration, type of cables laid in them, fire load and aerodynamic characteristics. This can lead to that temperature regime of fire in such tunnels may differ from the standard time-temperature curve and from each other. In this case it is not possible to guarantee compliance of the fire resistance rating of the tested structures with the current standards. Moreover, in this case the safety of people and property during fires in cable tunnels can be significantly reduced. In order not to conduct expensive tests to study this issue it is possible to carry out such studies based on the results of computational experiments. Modeling as a method of scientific research makes it possible to conduct all the necessary experiments to determine the temperature of fire in cable tunnels without performing expensive and time-consuming field experiments on models; moreover, it allows justification of the temperature of fire in cable tunnels to test building structures used during their construction for fire resistance as the basis for assessing of the fire resistance of enclosing structures.