can i ask how do you work out the allowable loading's on a cantilever brace compared to the angle..im assuming that the loads was taken from the safe axial loads but surely this is based on a vertical tube within the allowable deviations. in the old guidance it was always 30 to 35 degrees for cantilever braces but in the the new tg20 guidance there is nothing now...?
cheers
OW
"Triangulation"
Unless I misunderstand your question I feel you may have the horse before the cart.
I think you are asking about a brace being used as a spur to prop a cantilever. If not then I have misunderstood.
You would normally calculate the vertical load to be propped by the brace.
Once you have this you would resolve the vertical load through the brace angle using triangulation or trigonometry. As Scaffolders we would normally be working with a right angle somewhere in our triangle so:
The easiest way I find to explain this is as follows:
Pythagorean theorem
The length of the hypotenuse (Brace) is equal to, The square of the sum of the other two sides.
So consider the following
You are spuring the outer leg of an independent scaffold which is 1.2m wide in 2.0m lifts. The load in your outer leg is say 10kN
To find the load in your brace:
start by finding the brace length
You need the square route of (1.2x1.2)+(2x2)= 2.33m
Consider you 10kN as you vertical dimension and times it by your brace length=
10kN/2m =5 x 2.33m = 11.65kN in your brace thus you would need adequate couplers to support 11.65kN
You could reverse the process if you wanted to know the maximum vertical load which could be placed on a single coupler on your brace.
It sounded simpler in my head.
Good luck
Alan