RELIABILITY ASSESSMENT OF DAMAGED RC FRAMED STRUCTURES

Conventional design does not exclude risk of local damage to a structu re due to accidental events. Safety of the structure can be improved b y ensuring that failure of any of its components does not cause, withi n 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 probab ilistic method. The method is based on a combination of a nonlinear fi nite-element structural model and a first-order reliability method. Un certainties in material properties, geometry, loads, and the structura l model itself are taken into account, and their influence on frame re liability is considered. The uncertain parameters appropriate td the s trength of reinforcing steel, live load, and the model uncertainty are found to have a major influence on the frame reliability. For three-s pan frames with different numbers of stories and span-length ratios, c ritical cases of column failures are identified. As a result it is pos sible to restrict the number of examined structures. Finally, a simpli fied probabilistic method is proposed for the reliability assessment o f damaged frame structures.