Double Angle Verticle Braces 3

[eit09]

I am using double angle verticle braces. I call out spacer blocks (Plate in between the two angles) every 4' (Standard procedure at old job used for years). Wondering what others use for spacing of these spacer blocks?

 

[mrpid]

Take a look at AISC Specification E6. This should answer your question.

 

[BAretired]

I am not familiar with the spec mentioned by mrpid. The way I would do it is to space the plates so that sp/r is no greater than L/R where:

sp = spacing of plates
r = least principal radium of gyration of single angle
L = length of double angle
R = least radius of gyration of double angle

BA

 

[CTW]

See also AISC Specification for Structural Steel Buildings section D4 if your braces are in tension. Page 13-2 of AISC Steel Construction Manual Third Edition provides further explanation. This page also notes that a minimum of two stitch-fillers are required.

 

[slickdeals]

@BA:
The AISC Spec suggests that a/ri not greater than 0.75 l/r

a = spacing
ri = radius of gyration of individual component

 

[BAretired]

slickdeals,

Would your term ri be the least principal radius of gyration of the individual component?

BA

 

[slickdeals]

Yes, ri = minimum radius of gyration of individual component.

 

[BAretired]

O.K. That seems a touch conservative to me but I can't really argue with it. It is certainly safe.

BA