Wind Load Analysis
Mean Roof Height =
R HE + R E 2
=
8.5+6 2
= 7.25 m
2.5 4 θ = 32.005o
tan θ =
P.1-6; Table 103-1 Occupancy Category: IV – Standard Occupancy
P.2-38; Figure 207A.5-1A to 5-10 V = 250 km/hr V = 69.44 m/s
P.2-42 Kd = 0.85
P.2-47 Kzt = 1
P.2-67; Section 207B.32 qz = 0.613 Kz Kzt Kd V2 qz = 0.613 (Kz) (1) (0.85) (69.44)2 qz = 2512.4581 Kz
P.2-68; Section 207B4.1 P = q GCp – qi GCpi; Pa (N/m2)
P.2-55; Section 207A.9.1 G = 0.85 Use qi = qh Use q = 2512.4581 Kz
P.2-42; Section 207A.7.3 Exposure Category = B qi = 2512.4581 Kz
P.2-68; Table 207B.3-1 Kz = use hmean h 6 7.25 7.5
6−7.25 6−7.5
Kz 0.62 Kz 0.66
=
0.62−K z 0.62−0.66
Kz = 0.653 qi = 2512.4581 Kz qi = 2512.4581 (0.653) qi = 1640.635 Pa P = q (0.85) (Cp) – (1640.635) ( ± 0.18 ) P = 0.85 q Cp ± 295.314
Solving P for each face of the building
i.
Windward Roof; use q = qh = qi (Cp is in P.2-74) @ θ = 32.005o h 7.25 = L 8
= 0.906
h/L
Cp 32.005o X1 X2 Cp1 Cp2 Y1 Y2
30o -0.2 0.2 A1 A2 -0.3 0.2
0.5 0.906 ≥10
(For 30o – Vertical Direction) 0.5−0.906 0.5−10
=
−0.2− A 1 −0.2−(−0.3)
0.5−0.906 0.5−10
=
0.2− A 2 0.2−0.2
≈ A1 = -0.204
≈ A2 = 0.2
(For 35o – Vertical Direction) 0.5−0.906 0.5−10
=
−0.2−B 1 −0.2−(−0.2)
0.5−0.906 0.5−10
=
0.3−B 2 0.3−0.2
≈ B1 = -0.2
≈ B2 = 0.279
(For 0.5 – Horizontal Direction) 0
30 −32.005 0 o 30 −35
o
30 0−32.005o 30 0−35o
=
−0.2−X 1 −0.2−(−0.2)
=
0.2−X 2 0.2−0.3
≈ X1 = -0.2
≈ X2 = 0.2401
35o -0.2 0.3 B1 B2 -0.2 0.2
(For ≥10 – Horizontal Direction) 30 0−32.005o 30 0−35o
=
−0.3−Y 1 −0.3−(−0.2)
30 0−32.005o 0 o 30 −35
=
0.2−Y 2 0.2−0.2
≈ Y1 = -0.2599
≈ Y2 = 0.2
(For 0.906 – Horizontal Direction) 30 0−32.005o 0 o 30 −35 0
30 −32.005 0 o 30 −35
=
−0.204−Cp 1 −0.204−(−0.2)
=
0.2−Cp2 0.2−0.279
o
≈ Cp2 = 0.232
Using +GCpi; Using Cp = -0.202 P = 0.85 q Cp + 295.314 P = 0.85 (1640.635) (-0.202) +¿ 295.314 P = 13.617 Pa Using -GCpi; Using Cp = -0.202 P = 0.85 q Cp - 295.314 P = 0.85 (1640.635) (-0.202) P = -577.011 Pa
– 295.314
Using +GCpi; Using Cp = 0.232 P = 0.85 q Cp + 295.314 P = 0.85 (1640.635) (0.232) +¿ 295.314 P = 618.847 Pa = 2.919 kN/m Using -GCpi; Using Cp = 0.232 P = 0.85 q Cp - 295.314 P = 0.85 (1640.635) (0.232) P = 28.219 Pa ii.
– 295.314
Leeward Roof; use q = qh = qi h/L
Cp ≥20o
≈ Cp1 = -0.202
0.5 0.906 ≥10 0.5−0.906 0.5−10
-0.6 Cp -0.6 =
−0.6−Cp −0.6−(−0.6)
≈ Cp = -0.6
Using +GCpi; Using Cp = -0.6 P = 0.85 q Cp + 295.314 P = 0.85 (1640.635) (-0.6) +¿ 295.314 P = -541.41 Pa = -2.554 kN/m Using -GCpi; Using Cp = -0.6 P = 0.85 q Cp – 295.314 P = 0.85 (1640.635) (-0.6) P = -1132.038 Pa iii.
– 295.314
Windward Wall Cp is in P.2-74 Cp = 0.8 L=8m B=7m
L/B = 1.143
Use q = qz = 2512.4581 Kz (Use all values) hmean = 7.25 m (Use only up to “6”) Using +GCpi; Using Kz = 0.57 for h = 0 – 4.5 P = 0.85 q Cp + 295.314 P = 0.85 (2512.4581) (0.57) (0.8) + 295.314 P = 1269.143 Pa = 1.269 kN/m Using +GCpi; Using Kz = 0.62 for h = 6
P = 0.85 q Cp + 295.314 P = 0.85 (2512.4581) (0.62) (0.8) + 295.314 P = 1354.566 Pa = 8.127 kN/m Using -GCpi; Using Kz = 0.57 for h = 0 – 4.5 P = 0.85 q Cp – 295.314 P = 0.85 (2512.4581) (0.57) (0.8) – 295.314 P = 678.515 Pa Using -GCpi; Using Kz = 0.62 for h = 6 P = 0.85 q Cp – 295.314 P = 0.85 (2512.4581) (0.62) (0.8) – 295.314 P = 763.938 Pa iv.
Leeward Wall Cp is in P.2-74 L=8m B=7m
L/B = 1.143
L/B 0-1 1.143 2 1−1.143 1−2
Cp -0.5 Cp -0.3
=
−0.5−Cp −0.5−(−0.3)
≈ Cp = -0.4714
Use q = qh = qi qi = 1640.635 Pa Using +GCpi P = 0.85 q Cp + 295.314 P = 0.85 (1640.635) (-0.4714) + 295.314 P = -362.072 Pa Using -GCpi P = 0.85 q Cp – 295.314 P = 0.85 (1640.635) (-0.4714) – 295.314 P = -952.700 Pa