Slender member is subjected to axial load and biaxial bending moment and fails due to buckling. This buckling is
caused due to slenderness effect also known as ‘P∆’ effect. This buckling gives rise to excessive bending moment occurring at a
point of maximum deflection. This additional bending moment is considered in second order analysis. The objective of the
research reported in this paper is to formulate bending moment equation by using beam column theory and to study the
behaviour of solid circular section and hollow circular section of bridge pier.