THEORETICAL STUDY OF LONGITUDINAL COLUMNS (BI-AXIALLY LOADED) WITH REFERENCES TO VARIOUS CODES AND RESEARCHER’S COMPARATIVE ANALYSIS

Due to high complexity of common procedures, practical design of slender bi-axially loaded RC columns uses simplified approach, usually related to many concern and inconsistencies. Since such columns are unavoidable in building structures, more right design action is still of present interest. Beams and girders transfer their end moments into the corner columns of a structure frame in two perpendicular planes. Interior columns may also have biaxial moment if the layout of the column is uneven .For that reason such columns are designed consider axial load with biaxial bending. The biaxial bending moment may be resulted from the space action of the entire frame system or from an axial compressive load bi-axially located with respect to the major axes of the column cross section. On the other hand the long column is not something but the column so slender that it will fail under longitudinal load by bending rather than by crushing and have a length of 20 to 30 times the diameter also having the ratio of useful length to least lateral measurement is greater than 12.