Recent progress in understanding of load resisting mechanisms for mitigating progressive collapse

Document Type

Conference Proceeding


The collapses of Murrah Federal Building, Oklahoma City, in 1995 and Twin Towers of World Trade Center, New York City, in 2001 demonstrated that mass casualties and economic loss can be attributed to the collapse of buildings rather than the initial blast pressure or shock. Thus, designing buildings to prevent progressive collapse has become an imperative in the professional engineering community and standard-writing group in recent years with the increase of terrorist activities. However, it is uneconomical to design structures to resist progressive collapse purely relying on the flexural strength, as progressive collapse is an inherently low-probability event. Fortunately, existing studies indicated that there are some secondary load-resisting mechanisms neglected in conventional structural designs. These secondary mechanisms, depending on the locations of missing columns and types of structures implicated, can be utilized to mitigate the vulnerability of structures to collapse. This paper provides an overview of the advance of understanding in possible load-resisting mechanisms (Vierendeel action, compressive arch action, compressive membrane action, tensile catenary action, tensile membrane action, and dowel action) to resist progressive collapse of RC structures (frames and flat plate/slab).


Catenary; Compressive arch action; Dowel action; Load resisting mechanism; Membrane action; Progressive collapse; Vierendeel action