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.
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