Which of the following statements is INCORRECT in relation to the RCC column design according to IS 456: 2000?

Concept:

As per IS 456:2000, the minimum eccentricity for column design is given by:

\( e_{min} = \frac{L_{eff}}{500} + \frac{D}{30} \), subject to a minimum of 20 mm.

Where: • \( L_{eff} \) = Unsupported length of the column • \( D \) = Lateral dimension of the column

According to Clause 25.3.1 of IS 456:2000:
• The unsupported length between end restraints shall not exceed 60 times the least lateral dimension of a column.

According to Clause 25.3.2 of IS 456:2000:
• If one end of a column is unrestrained, its unsupported length shall not exceed \( \frac{100 b^2}{D} \), where b = width and D = depth of cross-section in the considered plane.

The unsupported length is defined as the clear distance between end restraints.

Incorrect Statement (as per question):

"All columns shall be designed for minimum eccentricity equal to (Unsupported length of column/30 + Lateral dimensions/500) subject to a minimum of 30 mm."

This is incorrect because:
• The formula used is wrong (L/30 + D/500 instead of L/500 + D/30)
• Minimum eccentricity should be 20 mm (not 30 mm)

Final Answer: Incorrect Statement is the first option