In order to help engineers better understand the behavior of concrete columns and to select an appropriate model for estimating the column capacity, a column classification method is required in engineering practice. Moreover, the information of the expected column failure mode (or column response) is helpful for engineers involved in the seismic assessment and retrofit of reinforced concrete buildings. This paper provides an approach to construct a probabilistic failure mode for concrete columns. The onset of column failure is defined as 20% loss in the lateral strength and three column failure modes (flexure failure, shear failure and flexure-shear failure) are considered. The database that consists of tests of reinforced concrete columns are divided into three categories in terms of span to depth ratio.The methodology developed by Gardoni et al. (2002) is adopted to construct the probabilistic capacity models for reinforced concrete columns.
