Content

• Steps
• Method 1 of 1: Calculating Wind Load

Strong winds can be very destructive. Wind speed - acts as pressure when it meets a structure. The force of this pressure is the wind load. Wind load calculations are essential for the design and construction of safer, more wind-resistant buildings. There are many factors to consider when calculating wind load, so see step 1 below to get started.

Steps

Method 1 of 1: Calculating Wind Load

1. 1 Be aware that wind speeds vary at different distances from the ground.
   • The wind speed increases with the height of the building.
   • Wind speed is most unpredictable closer to the ground, because it depends on interactions with objects on the ground.
   • This unpredictability makes accurate wind calculations difficult.
2. 2 Find the value for wind loads using the formula, wind pressure (Psf) = .00256 x V ^ 2.
   • V is the wind speed in miles per hour.
   • An alternative to calculating wind pressure at a specific wind speed is to use a standard for different wind zones. For example, according to the Electronic Industries Association (EIA), most of the United States is in Zone A with wind speeds of 86.6 mph (139.3 km / h), but coastal areas can lie in Zone B (100 mph or 160 , 9 km / h)) or Zone C (111.8 mph or 179.9 km / h)).
3. 3 Calculate the drag coefficient. Frontal drag is the pressure that an object is subjected to. One of the factors that determines resistance is the coefficient of resistance, which is determined by the shape and other factors of the object. The following drag factors are used in calculating wind load:
   • 1.2 for long cylindrical tubes or 0.8 for short cylinders such as antenna tubes found on some buildings.
   • 2.0 for long flat plates or 1.4 for shorter flat plates such as a building façade.
   • The difference between the coefficient of resistance for flat and cylindrical elements is approximately 0.6.
4. 4 Calculate wind load or force using the general formula F = A x P x Cd. ... Multiply the wind pressure area and drag coefficient.
   • F is strength.
   • A - area.
   • P is the wind pressure.
   • Cd is the coefficient of resistance.
5. 5 Use the new version of the formula developed by the Electronic Industries Association: F = A x P x Cd X Kz x Gh. This formula also takes into account:
   • Kz is the exposure factor, calculated as [z / 33] ^ (2/7) where z is the height from the ground to the middle of the subject.
   • Gh is the gust sensitivity coefficient and is calculated as .65 + .60 / (h / 33) ^ (1/7), where h is the height of the object.
6. 6 Consider the UBC '97 formula, which is the 1197 version of the "Uniform Building Code" for calculating wind for load. Formula - load or force in the area of ​​the object on the wind pressure. The difference is that the wind pressure (Psf) is calculated as Ce x Cq x Qs.
7. 7 Ce is a number taken from a table with three terrain exposures at different heights and Ce values ​​for each.
   • Cq - pressure coefficient or resistance coefficient.
   • Qs is the wind braking pressure taken from another UBC table.