Loads; Checking The Truss Beams; Anchorages Of The Extremties - Marcegaglia Buildtech Realpont system 75 Instruction Manual

Truss beam in tube-coupler
anchorage

LOADS

The wind pressure (Pw) is calculated according to the regulations and
standards in force and the project diagrams applicable to the scaffolding
surface exposed to the wind. The nodal load acting on the truss beam
anchorages must be calculated.
• horizontal truss beam
For example for diagram No. 1 in the 'Truss beam in tube-coupler an-
chorage' section, there must be 2 modules on every node.
The result is the following:
Q =P x 2S
o w w
A static layout of horizontal truss beam anchorages:
Q Q Q
0 0 0
R
0
• vertical truss beam
For example, in design no. 2 in the "Truss beam in tube-coupler ancho-
rage' section, there must be 2 modules on every node. The result is the
following:
Q =P x 2S
v w w
Static diagram of the anchoring vertical truss beam
Q
v
Q
v
Q
v
Q
v
Q
v
Q Q Q
0 0 0
R
v
R
v

CHECKING THE TRUSS BEAMS

Having defined the acting loads and the static diagrams as explained in
the previous section, proceed with defining the truss beams using the
Ritter method or models utilizing finished elements or whatever other
methods are available for the purpose of obtaining the maximum stress
loads:
Tmax = maximum shear action
Mmax = maximum bending moment
• horizontal anchorage beam
Use tubes of ∅ 48.3 x 3.2 steel 235JRH for constructing the beams
described in the previous sections.
Both the transoms and the diagonals of the beans are added to the scaf-
folding structure and immediately laid underneath the metallic decking
which forms the work bays.
Such beam elements will therefore only be subject to loads arising from
Q
0
the results of the preceding sections.
Therefore resistance and instability checks are carried out on the tran-
soms and diagonals most subject to stress.
• vertical anchorage beams
The diagonals are made of tubes ∅ 48.3 x 3.2 in S235JRH steel coupled
R
to the transoms with swivel joints, while the beam transoms take advan-
0
tage of the scaffolding uprights.
The resistance and instability checks of the scaffolding uprights must
therefore take into account both the vertical loads of traditional scaffol-
ding on the uprights and the loads consequent to the bending moment
acting on the vertical truss beam.

ANCHORAGES OF THE EXTREMTIES

Every truss beam must be anchored to the part it is serving.
Refer to the anchorage types already described and see previous section
for the checks that have to be carried out.
WARNINGS
It is recommended to check the following:
• check the tightening torque of the joints
• check for the presence of metal ledger boards on bays which act as
horizontal load dividers
• depending on the type of anchorages placed on the end of the truss
beams, see the applicable warnings that apply to each under 'Warnings' .
Instruction manual Prefabricated frames
44
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