What does the term “unsupported length” refer to in structural design, particularly for columns?
- AThe total height of a column from the base to the top.
- BThe portion of the column that is free to buckle without lateral support.
- CThe distance between two consecutive lateral supports.Correct
- DThe portion of the column that is designed to carry the maximum load.
Solution
Concept
Unsupported length in column design
Formula
NONE
Step-by-step solution
1. Unsupported length is the clear distance between lateral supports along a structural member. Answer: C
Explanation
Unsupported length is the clear distance between structural points that provide effective lateral bracing against displacement or buckling. This length directly influences the column slenderness ratio and its ultimate buckling resistance. Therefore, option C accurately defines the term unsupported length for column design.
Why the other options are wrong
A) Total column height includes supported and unsupported segments rather than just the unsupported length. B) The length free to buckle laterally defines effective length, not the specified option D.
Shortcut
Unsupported length is the distance between two consecutive lateral supports.
Common mistake
Confusing unsupported length with the total height of the column and selecting option A.
Correct answer: C) The distance between two consecutive lateral supports.