Progressive Collapse: Design Strategies

Abstract

Local failure of one structural element may result in the failure of another element of the same structure. Failure might thus progress throughout a major part or all of the structure. Design criteria for preventing such a progression of collapse are discussed. Investigative methods and design strategies for creating collapse-resistant structures are presented and compared. In addition to the better-known approaches providing specific local resistance or alternate load paths, an approach based on isolation of collapsing sections is described and discussed.

Progressive Collapse of Structures: Nomenclature and Procedures

“…In contrast to the design strategy "high safety against local failure," these key elements are under the control of the engineer: they are selected by choosing the alternate load paths or the locations of compartment borders, a design freedom whose magnitude depends on the design objectives. Thus, the num ber of key ele ments can be comparatively small, particularly when the compartmentalization approach is utilized (see [7,9,10] for further discussion and substantiation).…”

“…The prediction of the structural response to local failure requires suitable verifi cation procedures. It is suggested to use deterministic structural analyses, which should be as accurate as possible and consider all relevant scenarios [7,9,10]. The proper choice of triggering events and, if necessary, simplified analysis methods highly depends on the structure at hand and requires genuine engineering work [6,11].…”

“…The exposure can be considered par ticularly high for public buildings, major bridges, and other lifeline structures. If collapse resistance is deemed necessary, the following design objectives must be specified: These design strategies are described in more detail in [7,9,10]. It is of interest to note that the assumable extent of accidental circumstances (design objective a) must be specified only if the design strategy "high safety against local failure" is used.…”

“…Isolating an incipient collapse by compartmentalization requires either a strengthening or a reduction of continuity at the compartment borders. In other words, the compartment borders must be able to sustain either large forces or large displacements [9,10]. The compartmentalization approach, including the consequence of reducing continuity, has been applied to the design of the Confedera tion Bridge, Canada [6,11].…”

Evaluation of Progressive Collapse Resistance of Multi-Storey RC Building by Linear Static Analysis Method

“…Behavior of RC flat slab frame building under progressive collapse was studied by Seweryn Kokat et al [6]. Progressive collapse assessment of framed reinforced concrete 10 story building according to UFC guidelines for alternate load path method was carried out by Hamed Salem et al [7], Nonlinear dynamic analysis has been done by using Applied Element method (AEM). A set of design criteria for collapse resistance structure was proposed by by Uwe Starossek et al [8].…”