Strength of slender reinforced concrete columns under biaxial bending

A simple approach is proposed in this paper for estimating the strength of a slender reinforced concrete column under biaxial bending and axial load. The model considers the nonlinear stress-strain relations of concrete and r einforcing steel, and can be used for slender reinforced concrete column wi th arbitrary cross section. The problem of finding the strength of the slen der reinforced concrete column is formulated as a nonlinearly constrained o ptimization problem. The method is capable of predicting the slender column strength. Its use for design purposes is also outlined. The predicted resu lts obtained from the proposed method compare well with experimental result s found in the literature.