Investigation of Fire Resistance of Suspendome with Stacked Arch under Roof Spreading Fire

Derived from the principles of tensegrity, a suspendome is a hybrid structural system that integrates a rigid latticed shell with a flexible cable-supported system. Due to their high performance and aesthetic appeal, suspendome structures are widely employed in important public buildings. Aging wiring and improper welding operations are potential ignition sources for roof fires. Once ignited, the fire propagates along combustible roof materials, a phenomenon termed a roof spreading fire. Roof spreading fires are close to roof load-bearing steel structures, jeopardizing building safety and human life. This paper investigated the roof fire spread mechanism in a suspendome structure. Theoretical derivations of key fire source parameters assuming constant spread speed were established, a quadratic mesh delineation method is proposed, and a Fire Dynamics Simulator-Python (FDS-Python)–based program was created to compute the temperature field of dome fire. By considering various fire source locations and spread speeds, the plume temperature, structural temperature, and failure time of the structure were analyzed. An empirical prediction equation for the failure time of suspendome structures under roof spreading fire is proposed. The results indicated a pronounced center accumulation effect when the fire originated at the dome center, leading to rapid plume temperature escalation and a peak plume temperature of 1,056.6°C. The most detrimental fire source locations were identified as the center and the half-radius of the suspendome structure. The lowest failure time of the suspendome structure was determined to be 691.3 s. As the fire spread speed increased, the fire temperature increased rapidly, and the failure time of the structure continuously decreased. When the fire spread speed was below 5.0 mm/s, the failure time of the suspendome significantly increased.