Question

Which of the following is true about effective length?

(a) effective length shall be taken as length between inner end bolts/rivets of bars for single lacings

(b) effective length shall be taken as length between inner end bolts/rivets of bars for double lacings

(c) for welded bars, effective length shall be taken as 0.9 times distance between  inner end welds connecting single bars to members

(d) effective length shall be taken as 1.5 times length between inner end bolts/rivets of bars for double lacings

I got this question during an internship interview.

This intriguing question comes from Lacings in division Design of Compression Members of Design of Steel Structures

Answer 1

The correct option is (a) effective length shall be taken as length between inner end bolts/rivets of bars for single lacings

For explanation I would say: Effective length shall be taken as length between inner end bolts/rivets of bars for single lacings and 0.7 times length between inner end bolts/rivets of bars for double lacings. For welded bars, effective length shall be taken as 0.7 times distance between  inner end welds connecting single bars to members.