Advanced Package Training Scaffolding 2011.1 - Scia-Software GbR

1 2
q p ( z)
= ce
( z)
⋅ qb
= ce
( z)
⋅ ⋅ ρ ⋅ vb
2
where
ρ = 1,25 kg/m³
[ ] ( ) ( ) 2
2
1 + 7 ⋅ I ( z)
⋅ c ( z)
⋅ c ( )
ce v
r
( z)
=
z
kl
I v ( z)
=
⎛
c0
( z)
⋅ ln ⎜
⎝
I v v
( z)
= I z
( )
min
z
z
0
⎞
⎟
⎠
0
for
for
19
z ≤ z ≤ z
min
z ≤ zmin
kl is the turbulence factor. The recommended value for kl is 1,0.
These formulas evaluated for this example and category III gives:
kl
I v ( z)
=
⎛
c0
( z)
⋅ ln ⎜
⎝
z
z
0
1,
0
==
=
⎞ ⎛ 11 ⎞
⎟ 1,
0 ⋅ ln⎜
⎟
⎠ ⎝ 0,
3⎠
0,
278
2
2
2 2
[ 1 + 7 ⋅ I ( z)
] ⋅ ( c ( z)
) ⋅ ( c ( ) ) = [ 1 + 7 ⋅ 0,
278]
⋅ ( 0,
776)
⋅ ( 1,
0)
= 1,
77
ce v
r
( z)
= z
That way, the total external pressure is obtained by:
1
( z)
= ce
( z)
⋅ ⋅ ρ ⋅ v
2
2
q p
b
=
1,
77
⋅
0
1
2
⋅1,
25 ⋅
max
2 ( 26,
2)
N / m²
= 760N
/ m²
= 0,
76kN
/ m²
Scaffolding
Furthermore, we can assume that the members in the plane perpendicular on the wind load take up
about 1/5 (=20%) of the total surface of the construction, as shown on the drawing below: