Investigating the effect of restraints’ configuration on resistance of double layer braced barrel vaults to Progressive collapse

Abstract

Progressive collapse is a phenomenon in which a small localized damage spreads in different parts of the structure, and may damage the entire structure or a large part of it. Since the members in space structures only resist axial forces, these structures are more vulnerable to progressive collapse. One of the important factors in behaviour of these structures is the distribution of restraints. In this study, the effect of the configuration of supports on the resistance of double layer braced barrel vaults to progressive failure has been evaluated. To this end, five double layer braced barrel vault with height of 6.20 (m), covering area of 30 × 30 (m2), and different support arrangement was designed. Then, critical members were identified for each load combination. By removing critical members, dynamic load was applied to the structure and its behaviour was evaluated using nonlinear time histories analysis. Both nonlinear behaviour of materials and nonlinear geometric behaviour of members are considered in numerical simulation of models. Final responses show that the failure of members with higher stress ratio, results more dynamic force on structure which may cause progressive failure. However, eliminating members with lower stress ratio don’t cause progressive deterioration in structure. Furthermore, density of restraints has a great effect on the behaviour of double layer braced barrel vault and finding alternative stable path after removal of critical member.