[TowerTalk] Antenna & Tower Wind Load Ratings

[jimlux]

On 6/16/17 7:53 AM, Jim Thomson wrote:
> The below url pdf explains the 222-G spec in detail.
> http://www.towernx.com/downloads/TIA-222-G_Explained.pdf
>


t explains it but doesn't have all the various K factors, which in turn 
are from a whole bunch of tables.

For instance 2.6.5.2
Velocity Pressure Coefficient
Kz = 2.01(z/zg)^(2/alpha)
Kzmin <= Kz <= 2.01

z = height above ground level at base of structure
zg, alpha, and Kzmin are tabulated in Table 2-4

Exposure category B , Zg = 1200ft, alpha =7.0, Kzmin = 0.70, Ke=0.90, etc.


2.6.6.4 Topographic factor
Kzt = (1+ (Ke*Kt/Kh)^2

Kh = height reduction factor
  = exp(f*z/H)
Ke = terrain constant in Table 2-4
Kf = topographic constant in Table 2-5
f = height attenuation factor given in Table 2-5
z = height above ground level at base of structure
H = height of crest above surrounding terrain


and on and on.