Fire-induced Structural Failure Analysis of an Industrial Warehouse Roof Truss System

Fires are complex and hazardous phenomena governed by the laws of thermodynamics and fluid dynamics. Contrary to common belief, they are not rare occurrences, with approximately 130 buildings in Italy alone experiencing fires daily. The structural behavior under such extreme conditions is difficult to model as material mechanical properties are significantly influenced by temperatures, and thermal deformations alter structural responses. This paper focuses on investigating the fire scenario and the failure of a reinforced concrete industrial warehouse through dynamic fire simulations and nonlinear thermo-mechanical analyses. The warehouse roof is constructed with truss arches featuring three- hinged joints with a steel chain. The arches are regularly spaced at 5.0 m intervals, with a clear span of 19.40 m and a measured height of 8.40 m at the peak and 5.0 m at the supports. The study is composed of two fundamental phases: simulation of fire conditions using Fire Dynamics Simulator (FDS) and investigation of the structural elements collapse through finite element structural analysis. This analysis reveals that, due to thermal stresses, the chain in the roof truss can no longer perform its intended role within the arch, resulting in displacement at the ends and subsequent column collapse. Being a structure designed over 50 years ago, it lacks structural redundancy or robustness.