Laced Columns
Effective slenderness ratio of battened column shall be 1.05 times the maximum actual slenderness
ratio of column to account for shear deformation effects.
A laced column is stronger than battened column for same load
Width of Lacing Bars
In bolted/riveted construction, the minimum width of lacing bars shall be three times the nominal
diameter of the end bolt/rivet.
Laced Columns
Thickness of Lacing Bars
The thickness of flat lacing bars shall not be less than one-fortieth of its effective length for single
lacings and one-sixtieth of the effective length for double lacings.
Angle of Inclination
Lacing bars, whether in double. or single systems, shall be inclined at an angle not less than 40° nor
more than 70° to the axis of the built-up member
Laced Columns
Maximum spacing of lacing bars should be such that slenderness ratio of component member should
be not greater than 50
The slenderness ratio, KI/r, of the lacing bars shall not exceed 145
The lacing shall be proportioned to resist a total transverse shear, Vt, at any point in the member,
equal to at least 2.5 percent of the axial force in the member and shall be divided equally among all
transverse lacing systems in parallel planes.
Battened Columns
Effective slenderness ratio of battened column shall be 1.1 times the maximum actual slenderness
ratio of column to account for shear deformation effects.
A laced column is stronger than battened column for same load and effective length is increased by
only 5%.
Maximum spacing of batten should be such that slenderness ratio of component member should be
not greater than 50
Battened Columns
Battens should be designed to resist transverse shear force which is 2.5% of axial force
Thickness of batten plates shall not be less than 1/50th of distance between innermost connecting
transverse bolts/rivets
Effective depth of end batten should not be less than distance between centre of gravity of
component and should be greater than twice the width of component member.
Depth of intermediate batten = 3/4 depth of end batten
