# Sources of moment in columns

Thursday, September 15, 2011 11:48**Sources of moment in columns**:

Bending moment in column arises due to different reasons:

- Unequal loading on both sides of column.
- Unequal span on both sides of columns.
- Rigid frame action.
- Eccentricity of loads.
- Out-of-plumbness of column.
- Out-of-straightness of column.

**Explanation:**

**1. ****Unequal loading on both sides of column**

If the load is not equal than the total load will produce eccentricity with respect to center of gravity of column and hence moment will be generated.

**2. ****Unequal span on both sides of columns**

Due to different lengths of spans on both sides of column net moment will be created.

**3. ****Rigid frame action**

Due to monolithic behavior of column it behaves like a rigid joint and end moment of beam is transferred to the vertical strut.

**4. Eccentricity of loads **

When the load is applied at midpoint of column by means of brackets, moment is generated.

**5. ****Out-of plumbness of column **

If the strut is not vertical then at the top produces some moment below it.

**6. ****Out-of-straightness of column**

If the strut is not exactly straight then moment will be generated.