Economic design of reinforced concrete columns under direct load and uniaxial moments

Columns are important structural elements constructed integrally with framing concrete beams and slabs to provide resistance to both axial forces and bending moments. A key aspect in the design of columns is the strength of the column cross-section subjected to combine ‘axial force’ and ‘bending moment’. Designing a reinforced concrete (RC) column to resist an axial load and uniaxial moment is an iterative procedure which involves tedious calculations. The design is affected by many factors such as eccentricity of loading, size of the column cross section, percentage of steel, position of neutral axis, grade of steel, and grade of concrete, thereby requiring the use of interaction diagrams. In the present study, an attempt has been made to determine optimum design of reinforced concrete columns under direct load and uniaxial moments that satisfies all code requirements of IS 456-2000 and also results in minimum cost thereby. The ‘percentage of reinforcement’ and ‘depth of neutral axis’ are considered as design variables and using the capacity of swarm intelligence i.e. particle swarm optimization technique based on inertia weight, optimum design of RC column has been achieved. Some design examples are presented to demonstrate usefulness of swarm intelligence algorithm. © 2016 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.