Experimental Investigation of the Structural Response of a Steel-Framed Building Subjected to Traveling Fire

Abstract

This paper presents experimental investigations on the thermal response and structural behavior of a full-scale, 2-story, steel-framed building exposed to traveling fire. In this test protocol, the fuel bed consisted of 6.6-m3 pine cribs and then ignited from one end. Thermal and structural responses of the steel-framed building were measured throughout the fire, from which unsteady spreading and burnout rates of the fire could be obtained. Multiple temperature peaks and drastic temperature gradients were observed as flames spread across the compartment, which, led the structural members to become successively displaced due to the short period of thermal action at peak temperature in one location. Fracturing of connecting bolts was observed, indicating these connections should be further strengthened in practical design. As a main failure mode, local deformation of the beam lower flange and web adjacent to beam-to-column joints was also found. The test results invalidated the homogeneous temperature assumption and provided important data for performance-based structural fire design in such large compartment fire scenarios.