WIND LOAD COMPUTATION OF TRUSS.docx

WIND LOAD COMPUTATION OF TRUSS

Z (height above the ground floor) = 8.2 m H (height above the ground floor to the center of the king post) = 6.2 m L (horizontal dimension measured parallel to wind direction) = 15 m From Figure 207-5 Internal Pressure Coefficients Partially Enclosed Building

 = +.  ( () )  = −.  () () From Section 207.5.8 Gust Effect Factor Rigid Buildings

 = .  From table 207-4 Velocity Pressure Exposure Coefficient (Case I), 21.14 m above ground level

 = .   From Table 207-3 Importance Factor for wind load,  Category III (Special Occupancy)

 = .15 From Section 207.5.7.2 Topographic Factor

   = .  From Table 207-2 Wind Directionality Factor  Buildings

 = .   From Table 207-1 Wind Zone for Different Provinces of the Philippines Zone 2 (Oriental ( Oriental Mindoro)

 =    

From Figure 207-6 External Pressure Coefficients, Cp

ℎ 

=

6.2 15

= 0.413

  = 22.14° Windward = −0.257 Leeward  = −0.6

DETERMINING THE VELOCITY PRESSURE, qz:

q=0.0000473(K z) (K zt) (K d) (V) 2 (Iw)

q=0.0000473(0.89) (1) (0.85) (240) 2 (1.15) q= 2.370229488 DETERMINING THE WIND PRESSURE ON THE WINDWARD ROOF:

Windward Roof Truss Coefficients, Cp

 = −. 

Ph=qGCp-qi (GCpi)

Ph (+0.55) = (2.370229488) (0.85) (-0.257)-(2.370229488) (0.55) Ph (+0.55) = -1.82140285 kPa Ph (-0.55) = (2.370229488) (0.85) (-0.257)-(2.370229488) (-0.55) Ph (-0.55) = 0.7858495867 kPa

DETERMINING THE WIND PRESSURE ON THE LEEWARD ROOF:

Leeward Roof Truss Coefficients, Cp

 = −. 

Ph=qGCp-qi (GCpi)

Ph (+0.55) = (2.370229488) (0.85) (-0.6)-(2.370229488) (0.55) Ph (+0.55) = -2.512443257 kPa Ph (-0.55) = (2.370229488) (0.85) (-0.6)-(2.370229488) (-0.55) Ph (-0.55) = 0.09480917952 kPa

WINDWARD ROOF LOAD: PWL = Ph (-0.55) x

Spacing Truss x Spacing Vertical Member 

PWL = 0.7858495867 kPa

x (2m) x (1m)

PWL = 1.571699173 kN

VCOMP = PWL x (10/10.82)

HCOMP = PWL x (4.13/10.82)

VCOMP = 1.571699173 x (10/10.82)

HCOMP = 1.571699173 x (4.13/10.82)

VCOMP = 1.4526 kN

HCOMP = 0.55445 kN

LEEWARD ROOF LOAD: PWL = Ph (+0.55) x

Spacing Truss x Spacing Vertical Member 

PWL =-2.512443257 kPa

x (2m) x (1m)

PWL = -5.0249 kN

VCOMP = PWL x (10/10.82)

HCOMP = PWL x (4.13/10.82)

VCOMP = -5.0249 x (10/10.82)

HCOMP = -5.0249 x (4.13/10.82)

VCOMP = -4.644 kN

HCOMP = -1.918 kN