Effect of fire propagation modelling on structural elements temperature of steel racks

Automated Rack-Supported Warehouses (ARSWs) are a particular type of steel racks that combine the structural efficiency of steel construction with automated machines for handling stored products. This work addressed the fire development in ARSW, by investigating the fire modelling which can be used in a multi-depth ARSW structure, by adopting zone models, and Computational Fluid Dynamics (CFD) ones. Since the traveling fire plays a key role in these peculiar structures, a simplified “multi-cells” fire model that allows vertical and horizontal propagation, is proposed. Starting from the results of an extensive experimental campaign, available in the literature, conducted on steel racks, criteria to evaluate the vertical and horizontal propagation times are provided. Finally, the criteria of the simplified fire model were also compared with the results of advanced CFD analyses, in which the traveling fire was naturally considered, showing a good agreement. This proposed “multi-cells” zone model provides a useful tool for both design and assessment of the fire behaviour of ARSW structures.