Civil Engineering - RCC Structures Design - Discussion

According to IS 456:2000 (Clause 25.1.2):

A column is considered long if the slenderness ratio exceeds 12 for design purposes.

However, in some multiple-choice questions or conceptual discussions (often academic or exam-focused), a value of 60 is typically used to differentiate between short and long columns more strictly especially when referencing unbraced lengths.

But based on IS 456:

Practically: If slenderness ratio > 12, the column is designed as a slender (long) column.

Theoretical/MCQ-based (competitive exams): The answer is usually 60.

I think it is 40.

I think 40 is the correct answer.

As per IS 456 and SP16 (clause 3.4 of compression members) if Slenderness ratio leff/LLD is more than 12 it is a long column. For steel structures, the Slenderness ratio is Leff/r min and its limiting value is 180.

S. N ratio for short column <41 or =41.

And for long column >41.

Yes, that means Slenderness limit should not exceed 60. Beyond that limited, a column can't be considered.

According to IS 456:2000 (Clause no.25.3.1).

The unsupported length between end restraints shall not exceed 60 times the least lateral dimension of a column.

According to is 456 2000, for long column λ should be less than 60.

This is based on l (effective) /radius of gyration.

I think option C 40 is correct.