Triangular brace
A triangular brace is a temporary structure used for access to elevated points that are sometimes difficult to reach. It is also used at times to support a portion of a building. Triangular braces are known by various names, including modular brace, triangular frame, omega brace, and scaffold.
Scaffolds are made up of various types, including: Triangular scaffold, hammer scaffold, and cuplock scaffold are different types of scaffolds. Here, we will elaborate on the triangular scaffold:
This type of scaffold consists of triangular frame units with sides measuring 120 centimeters and heights of 100, 75, and 50 centimeters, which are connected to each other in a male-female manner. Triangular scaffolds are used in the formwork of slabs or beams as well as the substructure of bridges. The assembly of triangular scaffolds is straightforward to the extent that two workers can easily set up more than a thousand units in a single day.
The other components that make up the triangular scaffold system include:
- Floor slab
- Support inclination (edge and diagonal)
- Adjustment Screw (Jack Screw)
- Stud (or Pin) for Formwork
A square-section scaffold, with each side measuring 120 centimeters and a height of 1 meter, is desired. It is assumed that in this triangular (omega) scaffolding, the diameter of the pipes is 50 millimeters, and the thickness of the sheet is 2.5 millimeters. We will have:
lx≫ly=〖πr〗^3 t→π(〖2∙5)〗^3×(0∙25)=12∙27〖cm〗^4
A→π(r_2^2-r_1^2 )=π{(〖2∙5〗^2 )-(〖2∙25〗^2 )}=3∙73〖cm〗^4
R=0∙7×2∙5=1∙76cm
K=1 L=100cm
S=kl/r→(1×100)/(1∙76)=56.8
(kl/r<Cc)→fa=Fy/Fs [1-0∙5((kl/R)/Cc)2]
F∙S=1∙67+0∙37((kl/r)/Cc)-0∙125((kl/r)/Cc)^3=1∙82
Fa=2400/(1∙82) [1-0∙5((56∙8)/(131∙4))]=1195kg
P=Fa×A=1195×3∙73=4457kg≈4∙4ton
– The load-bearing capacity of each triangular truss support with a square layout in this case is 13.2 tons.
Using triangular truss supports for the substructure of elevated concrete structures such as bridges and concrete beams is a reliable solution and a suitable alternative to ceiling jacks. Because ceiling jacks are usable at a maximum height of 5.5 meters and can bear a load of up to 1.5 tons per cross-braced ceiling jack within an 80-centimeter distance from each other. While triangular trussing, even with a 120-centimeter spacing between two frame assemblies, can easily and confidently withstand a concrete load of up to 3000 kilograms, even at a height of 10 meters.
Calculating the quantity of scuffles is done as follows:
Considering that the scuffle with a width of 120 centimeters, the scuffle is produced. Therefore, if the concrete pressure is assumed to be 3 tons per square meter, according to the layout shown below, it will be square. Assuming that we want to cover an area of 400 square meters with scuffles and consider a hypothetical height of 8 meters, the calculation of the number of scuffles will be as follows:
Triangular scuffles 100*120, a total of 1932 pieces
Triangular scuffles 50*120, a total of 276 pieces
Edge clamping rail 120 cm long, 276 pieces
Diameter clamping rail 170 cm long, 138 pieces
15 cm floor slab, 276 pieces
40 cm adjustment screw (head jack), 276 pieces
Therefore, the heavier the structure, according to the calculation table and layout shown below, the required number of skaffolds can be estimated based on the distance between frames.
Weight Table of Triangular Truss Components:
Modular Triangular Truss 100*120, 10.5 kilograms
Modular Triangular Truss 75*120, 9 kilograms
Modular Triangular Truss 50*120, 8 kilograms
Diameter Tie Rod 170 cm, 3.5 kilograms
Diagonal bracing 120 cm 3 kilograms
Heel plate 15 cm 1 kilogram
Therefore, based on the above table, the average weight of one cubic meter of triangular truss will be approximately 44 kilograms.
