Title:
Progressive Collapse of Reinforced Concrete Structures: A Multihazard Perspective
Author(s):
Mehrdad Sasani and Serkan Sagiroglu
Publication:
Structural Journal
Volume:
105
Issue:
1
Appears on pages(s):
96-103
Keywords:
bar fracture; brittle failure; integrity requirements; load redistribution; progressive collapse.
DOI:
10.14359/19073
Date:
1/1/2008
Abstract:
Through accident or act of terrorism, structures may be subject to conditions that could lead to progressive collapse. Redistribution of loads following an imposed local damage to a structure depends on strength, continuity, redundancy, and deformation and energy dissipation capacities of the structure. For reinforced concrete frame structures, these characteristics depend on the seismic and wind design loads to a great extent. In this paper, using the response of multi-degree-of-freedom and equivalent single-degreeof-freedom systems, it is demonstrated that the vulnerability of frame structures against progressive collapse caused by man-made hazards depends heavily on their resistance to natural hazards. It is also shown that following the loss of a column and in spite of satisfying the current structural integrity requirements, premature beam bottom bar fracture can occur. Such bar fracture can be avoided if the minimum beam bottom continuous bars are set equal to the minimum flexural reinforcement.