Collapse-resisting mechanism and damage propagation pattern of suspended-domes following sudden cable loss

Abstract

This paper aimed to reveal two important mechanisms that determine the survival of suspended-domes subjected to a sudden cable rupture scenario: the mechanism for the initial local damage to be arrested by the remaining structure, and, the mechanism for the local damage to propagate throughout the remaining structure in case it is not fully arrested. A test was performed on a scale-down suspended-dome model respecting all structural details. After one of the outer-ring hoop cables was suddenly ruptured by an innovative remotely-controlled cable-breaking device, the remaining structure established an alternative path at the outer ring, tying the remaining hoop cables, and thereby regained balance. Complementary finite-element analysis was performed and validated. Other cable rupture scenarios were investigated, for which the alternative path for hoop cables was also confirmed. The cable rupture-induced damage, characterised primarily by the relaxation of hoop cables, was able to transmit outwards and inwards to the other rings of the suspended-dome, during which the relaxation of diagonal cables was a critical step. The hoop cable relaxation propagated easier inwards than outwards, and the rupture of outer-ring hoop cable caused the most severe damage. The failure of a hoop cable and resultant relaxation of neighbouring cables would effectively turn the suspended-dome into a single-layer latticed dome within the local range of failure, and point buckling of the latticed dome may occur and even cause structural progressive collapse. The failure of one diagonal cable would hardly cause the hoop cable to relax and thus normally caused no further damage.