In Exposure C, how does wind typically behave?

• A. Wind direction remains constant with no pressure change
• B. Wind accelerates, resulting in higher wind pressures
• C. Wind gusts have no effect on pressure
• D. Wind slows down, reducing pressures

Answer: (B)

In wind loading, Exposure C represents rougher terrain where wind tends to be more gusty and accelerate around obstacles. The key idea is that wind pressure rises with wind speed, and gusts push the instantaneous pressure higher because dynamic pressure increases with the square of speed. So when wind accelerates and gusts occur, you get higher wind pressures on surfaces. That’s why the option describing wind accelerating and producing higher pressures is the best fit.

The other statements aren’t typical for Exposure C: wind rarely stays constant with no pressure change in such terrain; gusts do affect pressure, not be irrelevant to it; and while some sheltered areas can see slowed wind, Exposure C generally features accelerating wind rather than consistent slowdown, leading to increased pressures.