Wind Load Calculation for Pipe Rack

To calculate wind load on Pipe racks, open structures, cable trays and pipes as per ASCE 7-10, use the following approach, accounting for the cylindrical shape and exposure to wind.

For wind load calculations in metric units as per ASCE 7-10, the primary difference lies in the units for wind speed and pressure. Here’s how to calculate wind load using metric conversions:

1. Determine Basic Wind Speed (V)

  • Obtain wind speed (V) in meters per second (m/s) from ASCE 7-10 maps, converting as needed.

2. Calculate Velocity Pressure (q)

  • The velocity pressure q(z) at a height z in kPa (kiloPascal) can be calculated as: q(z)=0.613×Kz×Kzt×Kd×V2

where:

  • 0.613 = conversion factor to metric (in kPa) for air density,
  • V = basic wind speed in m/s,
  • Kz = velocity pressure exposure coefficient (from ASCE 7-10 Table 27.3-1),
  • Kzt = topographic factor,
  • Kd = wind directionality factor.

3. Exposure Category

  • Define Exposure Category (B, C, or D) based on the surrounding terrain, as this influences Kz​ values.

4. Calculate Projected Area (A)

  • Use the projected area per unit length of the cable tray or pipe:

A=D×L

where:

  • D = outer diameter of the pipe or effective width of the cable tray (m or ft),
  • L = length of the pipe or cable tray (m or ft).

5. Calculate Wind Load (F)

  • The wind force per unit length on the pipe or cable tray can be calculated as: F=q(z)×Cd×A

where:

  • F = wind load per unit length (kN/m or lb/ft),
  • q(z) = velocity pressure at height zzz,
  • Cd​ = drag coefficient,
  • A = projected area per unit length.

6. Consider Combined Effects

  • For long runs of cable trays or pipes, consider gust factors and structural sway, especially if elevated.

Example Calculation

For a pipe of 0.5m diameter at 10m above ground, in an exposure category C with a basic wind speed of 40 m/s:

  1. q(z)=0.613×Kz×V2
  2. A=D×L (D = 0.5 m)
  3. F=q(z)×Cd×A

Commercial Shop Plan

COMMERCIAL SHOP FLOOR PLAN   40’-0” x  60’-0” NORTH & SOUTH FACING Shop floor Plan ground…

Read More

Shop Floor Plan

Shop floor Plan ground floors, the floors are completely utilized without wastage. The plot size…

Read More
Almost there!
We are confirming your order with