Title:
Axial Load-Moment Interaction for Cross-Sections Having
Longitudinal Reinforcement Arranged in a Circle
Author(s):
Noel J. Everard
Publication:
Structural Journal
Volume:
94
Issue:
6
Appears on pages(s):
695-699
Keywords:
axial force; columns; compression; concrete; drilled piers;
inch-pound units; interaction diagrams; metric units; piles; reinforcement;
SI units; strain; stress; stress-strain relationships; units; yield stress.
DOI:
10.14359/9729
Date:
11/1/1997
Abstract:
Equations are derived for the computerization for the development of axial load-moment interaction diagrams for cross-sections having the longitudi-nal reinforcement arranged in a circular pattern. Although the equations for the contributions of the concrete cross-sections to axial load and moment are provided for circular members, the equations for the contributions of the reinforcement are equally applicable to any cross-section for which the gross cross-sectional area can be expressed as A a factor h times the enclosing rectangle area, DL. The equations were originally developed in 1962 to produce the interaction diagrams for square and circular cross-sections having the longitudinal reinforcement arranged in a circle that were published in ACI Special Publication SP-7.’ The resulting computer program was used to produce new axial load-moment interaction diagrams for the ACI Committee 340 Design Handbook? While the diagrams were plotted for columns having reinforcement ratios pg ranging from 0.01 to 0.08, the equations are equally applicable for use with drilled piers and piles having reinforcement ratios less than 0.01. The equations are based on statics and strain compatibility and conform completely with the intent of AU Code.3p4 The equations may be programmed for use with inch-pound units, SI units, or CGS metric units.