Experimental and Numerical Study on Progressive Collapse Analysis of a Glulam Frame Structure: I. Side Column Exposed to Fire

Abstract

This paper presents experimental and numerical investigations on progressive collapse behavior of a two-story glulam frame when the side column is exposed to ISO834 standard fire. The collapse mechanism initiated by fire is identified. The experimental results show that the progressive collapse of a glulam frame could be described for three stages, namely bending effect stage, catenary effect stage and failure stage, respectively. These stages are discussed in detail to understand the structural behavior before and during collapse. It is demonstrated that the entire frame slopes towards the side of the heated column, and the "overturning" collapse occurs eventually. The catenary effect of beams is the main reason for the progressive collapse of the frame. In addition, a finite element model of a glulam frame is established to simulate the progressive collapse behavior. The effects of axial loads on the columns are summarized. The numerical simulation results agree well with the experimental results, which could verify the effectiveness and practicability of finite element simulation. Furthermore, the progressive collapse resistance of the frame in practical design were proposed.