What is the effect of Exposure C on wind pressure?

What is the effect of Exposure C on wind pressure?

• A. Wind lowers uplift pressures
• B. Wind has no effect
• C. Wind accelerates, resulting in higher wind pressures
• D. Wind is slowed by obstructions

Answer: (C)

Exposure C describes open, unobstructed terrain. In these conditions the wind isn’t slowed by nearby buildings or other obstacles, so it can accelerate more as it moves across the terrain and up to the structure’s height. That higher wind speed increases the dynamic (velocity) pressure on the surfaces of the building, leading to higher wind pressures overall. So the effect is that wind accelerates, resulting in higher wind pressures.

Exposure C describes open, unobstructed terrain. In these conditions the wind isn’t slowed by nearby buildings or other obstacles, so it can accelerate more as it moves across the terrain and up to the structure’s height. That higher wind speed increases the dynamic (velocity) pressure on the surfaces of the building, leading to higher wind pressures overall. So the effect is that wind accelerates, resulting in higher wind pressures.