A review of progressive collapse research and regulations

Abstract

History has demonstrated that buildings designed to conventional design codes can lack the robustness necessary to withstand localised damage, partial or even complete collapse. This variable performance has led governmental organisations to seek ways of ensuring all buildings of significant size possess a minimum level of robustness. The research community has responded by advancing understanding of how structures behave when subjected to localised damage. Regulations and design recommendations have been developed to help ensure more consistent resilience in all framed buildings of significant size, and rigorous design approaches have been specified for buildings deemed potentially vulnerable to extreme loading events. This paper summarises some of the more important progressive collapse events, to identify key attributes that lead to vulnerability to collapse. Current procedures and guidelines for ensuring a minimum level of performance are reviewed and modelling methods for structures subjected to localised damage are described. These include increasingly sophisticated progressive collapse analysis procedures, including linear static and non-linear static analysis, as well as non-linear static pushover and linear dynamic methods. Finally, fully non-linear dynamic methods are considered. Building connections potentially represent the most vulnerable structural elements in steel-framed buildings; their failure can lead to progressive collapses. Steel connections also present difficulties with respect to frame modelling and this paper highlights benefits and drawbacks of some modelling procedures with respect to their treatment of connections.

Residual Axial Capacity of Reinforced Concrete Columns Subject to Internal Building Detonations

“…1,2 As a consequence, the general literature on internal building detonations and speci¯cally in the context of protective design and assessment of structures against these complex loading cases is inconclusive. In addition, existing assessment techniques developed for comparatively noncomplex external explosive blast remain unconservative when applied to internal building detonations due to blast wave con¯nement and complex interaction with structural components.…”

Editorial

“…The first paper, by Byfield et al (2014), is a review of progressive collapse research and regulations that summarises some of the most important progressive collapse events and aims to identify key attributes that lead to vulnerability to collapse. Methods and guidelines to ensure a minimum level of structural performance are reviewed and simulation approaches for structures subjected to localised damaged are described.…”

Análise mecânica e probabilística de estruturas treliçadas sujeitas ao colapso progressivo

“…Danos acidentais tais como explosões, impactos, ataques terroristas, ações excepcionais, erros humanos e de construção, frequentemente causam danos locais nas estruturas, os quais podem conceber sérias ameaças quando um ou mais elementos estruturais falham, implicando no colapso progressivo de toda a estrutura ou parte dela [75]. Por conseguinte, o colapso progressivo sempre é acompanhado por graves perdas humanas e materiais [76,77]. Fonte: Federal Emergency Management Agency (FEMA) [79].…”

“…Ainda não existem regras específicas para dimensionar uma estrutura contra o colapso progressivo [75,77,120]. Não obstante, pode-se apresentar quatro abordagens determinísticas empíricas indicadas pela literatura, as quais são utilizadas para garantir a resistência ao colapso, são elas: (i) regras prescritivas de forças de amarração; (ii) método dos caminhos de cargas alternativos; (iii) método da resistência local específica e (iv) isolamento por segmentação.…”

“…Os documentos DoD [82], GSA [85] e CECS [137] permitem análises estáticas lineares e não lineares 3 , além de análises não lineares dinâmicas. As vantagens e desvantagens de cada tipo de análise são discutidas por Byfiel et al [77].…”