Environmental Engineering Reference
In-Depth Information
Fig. 2.1 Wind zones to DIN 1055-4 [12]
The relationship between reference values for wind speed v ref and dynamic pressure
q ref is given by the following equation:
2
ð
v ref m
½
=
s
Þ
q ref kPa
½
¼
1600
When designing towers, only the reference dynamic pressures for terrain categories II
(inland) or I (wind zone 4 directly on the coast) should be assumed. Less onerous
terrain categories (III and higher) can be ruled out because the effects of the various
ground roughnesses decrease as the height of the structure increases.
Therefore, the combined profiles given in DIN 1055-4 [12] for structures up to 50m in
height should not be used either (see also Beton-Kalender 2006 [8]).
Prior to the introduction of DIN 1055-4 [12], the wind loads for tower-type structures
were calculated according to DIN 1056 [13] or annex A of DIN 4131 [14] or annex A of
DIN 4228 [15]. Beton-Kalender 2006 [8] compares the wind loads according to the old
standards and DIN 1055-4 [12].
2.3.1.1 Wind loads according to the DIBt guideline
According to DIN 1055-4, the following basic parameters apply (see Figure 2.2 and
Table 2.1):
- 50-year return wind v m50 (z)
- 50-year return gust v e50 (z)
 
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