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The functionality of community buildings not only depends on the damage to individual buildings but also on the interactions with other infrastructure systems. This paper incorporates these interactions by applying the systems thinking approach to analyze community resilience. The proposed framework starts with identifying the physical infrastructure systems and key components in a community. Then, the seismic hazard scenarios are defined, and the component damage and recovery are assessed by utilizing fragility and consequence functions. After that, a network model, considering the interdependencies between the utility networks and the dependency of utility networks on the community buildings, is introduced to evaluate the component-level building functionality. Finally, community resilience is assessed by proposing community-level indicators including inherent resilience, community functionality, and access to essential facilities. The proposed model is illustrated on a community consisting of building portfolios, water, and electric power systems under four hazard scenarios. It is concluded that the systems thinking approach considered at a community level provides important insights into community resilience such as building functionality, utility demand, and supply, and access to essential facilities, among others. [ABSTRACT FROM AUTHOR]

Existing buildings can be at a greater seismic risk due to non-conformance to current design codes and may require structural retrofitting to improve building performance. The performance of buildings is measured in terms of immediate consequences due to direct damage, but the continuing impacts related to recovery are not considered in seismic retrofit assessment. This paper introduces a framework of retrofit selection based on the seismic resilience of deficient buildings retrofitted with the conventional mitigation approaches. The assembly-based methodology is considered for the seismic resilience assessment by compiling a nonlinear numerical model and a building performance model. The collapse fragility is developed from the capacity curve, and the resulting social, economic, and environmental consequences are determined. The seismic resilience of a building is assessed by developing a downtime assessment methodology incorporating sequence of repairs, impeding factors, and utility availability. Five functionality states are developed for the building functionality given investigated time interval, and a functionality curve for each retrofit is determined. It is concluded that seismic resilience can be used as a performance indicator to assess the continuing impacts of a hazard for the retrofit selection. [ABSTRACT FROM AUTHOR]

Disproportionate or progressive collapse is a phenomenon in which entire structure or large part of it collapses because of the local failure of a structure. Resistance to such progressive collapse depends on continuity between elements and ductility of the connections. The ductility of commonly used bolted end plate connections may depend on the T-stub component of the connection. The aim of this paper is to study the behaviour of T-stub components of beam to column end plate bolted connections under large deformation demands associated with column loss scenario. For this purpose, a parametric study is carried out to evaluate the ultimate strength and deformation capacity considering two parameters i.e. distance between the bolts and endplate thickness. Based on the experimental data, numerical model has been validated and employed in a parametric numerical study aimed at improving the response under large deformation demands. The study indicate significant role of bolts in development of catenary forces since the ultimate tensile capacity of T-stub after undergoing large deformation in a ductile failure mode was controlled by the failure of the bolts. Parametric study reveals much higher bolt force in comparison with displacement controlled induced axial force in the T-stub indicating failure of the bolts at much lower applied axial force. [ABSTRACT FROM AUTHOR]