What is large eccentricity in concrete?
Large eccentricity in concrete is when the maximum moment is greater than:
- 0.1Puh (tied columns)
- 0.05Puh (spiral columns)
where:
Mu = the maximum moment
Pu = Factored axial load on the column
h = the dimension of the column perpendicular to the axis of bending
Pu = Factored axial load on the column
h = the dimension of the column perpendicular to the axis of bending
The easiest, quickest and fasted way to analyze large eccentricities in columns is to use the Concrete Column Interaction Diagrams if they are available for the shape/strength/reinforcement you plan on using.
Note: When designing a column from scratch it would greatly behoove you to use a column design for a concrete interaction diagram you have.