Test: Compression Members- 1 - Civil Engineering (CE) MCQ

Minimum width of lacing bars in riveted connection should be as follows:
Nominal rivet
diameter (mm)    22 20 18 16
Width of lacing bars (mm)     65 60 55 50

The lacing of compression members should be designed to resist a transverse shear, V = 2.5% of axial force in the member.
For single lacing system on two parallel faces, the force (compressive or tensile) in each bar,

For double lacing system on two parallel planes, the force (compressive or tensile) in each bar,

It is equivalent to a compression member whose one end is fixed against rotation and position and the other and neither restrained against rotation nor fixed in position in the direction perpendicular to wire. So effective length = 2L = 10 m.
In the direction of wire, the pole is hinged at wire end so effective length = 0.8L = 4.0 m.

Slenderness ratio, 
Lesser the value of λ (greater radius of gyration r), the column can take more load. Maximum radius of gyration is obtained when material is farthest from centroid. Therefore box section is best.

For single angle discontinuous,
(i) One rivet or bolt - Effective length is the distance between the centres of end fastenings
(ii) Two or more rivets or welding - Effective length is 0.85 times the distance between node points.

If the column ends and gusset materials are not faced/machined for complete be a ring, the fasteners are designed for the total forces to be transferred. If they are faced/machined for complete bearing, 50% of the forces are transferred directly by the column and 50% through the fasteners