Probabilistic evaluation of column overdesign factor through reliability analysis for typical failure modes

A probabilistic method through reliability analysis for typical failure modes is presented to evaluate the column overdesign factor η_c. This method aims to determine the optimal η_c that will cause the structural failure in form of 'strong column-weak beam' damage by calculating the failure probability of typical failure modes with the reliability theory. To illustrate the application of the presented method, a five-story reinforced concrete (RC) frame was used as the example, and total of three failure mechanisms involving the yield failure, ultimate deformation failure and shear failure were considered through selecting seven typical failure modes. Results show that the suggested η_c in current Chinese codes cannot ensure the occurrence of the 'strong column-weak beam' damage; while the example structure is most likely to undergo the 'strong column-weak beam' damage when η_c is greater than 3.1.