Title:
Designing Reinforced Concrete Short-tied Columns Using the Optimization Technique
Author(s):
Zenon A. ZielinskiI, Wenyi Long, and Michael S. Troitsky
Publication:
Structural Journal
Volume:
92
Issue:
5
Appears on pages(s):
619-626
Keywords:
columns (supports); computer programs; eccentric loads; optimization; reinforced concrete; structural design; Design
DOI:
10.14359/914
Date:
11/1/1995
Abstract:
A procedure for the design of reinforced rectangular short- tied columns using the optimization technique is presented. The proposed procedure includes two sets of iterations. The first set of iteration finds the resistance capacity of a column of given dimensions, and the second set of iteration performs the optimization process. The optimization process is formulated as finding the minimum cost design with the constraints imposed based on Canadian Specification CSA CAN3-A23.3-M84. The internal penalty function algorithm for nonlinear programming is used in the optimization procedure. The most difficult task in calculating the ultimate strength of a short column, particularly under biaxial loads, is to determine the position of the neutral axis. For a column with uniaxial loads, the depth, width of the cross section, and reinforcement ratio are treated as design variables, and the location of the neutral axis is obtained by solving a cubic equation. For a column with biaxial loads, the dimensions of the cross section, reinforcement ratio, and number of reinforcing bars are treated as design variables, and the location of the neutral axis is determined by employing the Newton-Raphson method. Numerical examples are given to show the validity of the proposed method.