Reliability Assessment of Damaged RC Framed Structures

Abstract

Conventional design does not exclude risk of local damage to a structure due to accidental events. Safety of the structure can be improved by ensuring that failure of any of its components does not cause, within an appropriate level of reliability, collapse of the whole structure or a major part of it. In this paper reliability of multistory framed structures subjected to column failure is investigated using a probabilistic method. The method is based on a combination of a nonlinear finite-element structural model and a first-order reliability method. Uncertainties in material properties, geometry, loads, and the structural model itself are taken into account, and their influence on frame reliability is considered. The uncertain parameters appropriate to the strength of reinforcing steel, live load, and the model uncertainty are found to have a major influence on the frame reliability. For three-span frames with different numbers of stories and span-length ratios, critical cases of column failures are identified. As a result it is possible to restrict the number of examined structures. Finally, a simplified probabilistic method is proposed for the reliability assessment of damaged frame structures.