Blast & Impact Loading & Response of Structures
Blast pressures can cause severe damage to building structures. There is also the possibility of a fire occurring as a result of a blast event. It is therefore imperative that key facilities that are exposed to these multi-hazards during their design life are properly designed against their actions. However, current structural fire design methods are only applicable to smaller compartments, since the distribution of temperatures is usually considered as uniform within the compartment. On the other hand, larger compartments can be designed for using The Travelling Fire Methodology which considers a more realistic distribution of temperatures in the compartment. The combined effects of blast pressures and travelling fires on the structural resistance of steel frames will be discussed. In the study, non-linear finite element analyses were carried out on prototypical office steel frames. Parametric analyses were then conducted to determine the effects of important parameters such as blast pressure, fire size and maximum compartment temperature on the steel frames. Different directions of travel for the fire were also considered in the analyses. The study revealed that increased blast pressures decreased the resistance of the frame to the travelling fires. Also, the response of the frame was different when different directions of the travelling fire were considered. The results also showed that smaller fire sizes with longer total fire durations may result in higher structural deformations. The study demonstrates the importance of considering travelling fires in multi-hazard scenarios and lends support for the use of the proposed methodology when designing for such multi-hazard scenarios.