Structural Response of Steel High Rise Buildings to Fire: System Characteristics and Failure Mechanisms

Due to the significant vertical elevation and complexity of the structural system, high rise buildings may suffer from the effects of fire more than other structures. For this reason, in addition to evacuation strategies and active fire protection, a careful consideration of structural response to fire is also very important. In this context, it is of interest to investigate the characteristics of the structural system that could possibly reduce local damages or mitigate the progression of failures in case of fire. In this paper, a steel high rise building is taken as case study and the response of the building is investigated up to the crisis of the structure with respect to a standard fire in a lower and in a higher storey: the comparison of the fire induced failures at the different height allows highlighting the role played in the resulting collapse mechanisms by the beam-column stiffness ratio and by the loading condition.