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# Civil Engineering/wind loads for a element

Question

A-frame
QUESTION: Dear sir,
I have a A-frame as attached in the picture, i have calculated the wind load on the member as per BS 6399, Using clause 2.7 (pressure coefficient for elements), got it as 0.4 Kn/m, Should it be applied in the four orthogonal directions (i.e 0 deg , 90 deg, 180 deg ,270 deg) or any one is sufficient? second doubt is should it be applied to the inclined member in the bottom  and horizontal member at the Top also?

Regards
BEH

---------- FOLLOW-UP ----------

QUESTION: can you briefly explain how suction is possible and how it should be calculated and where it should be applied? I assume suction is only possible inside buildings where internal pressure is created. but this is frame outside a building like a pole.correct me if iam wrong.

Dear Arsalan

When you blow on a stick of match 2 systems of forces act on it: Positive pressure + negative pressure both with  the same direction. If the stick is among a sheet of paper when you blow on it the suction ( negative pressure) is not likely to occur because your blow cant be stronge enough. Then for a member in free space you have a load around 1.5 to 1.8 times the positive pressure.

Regards
BEH

Civil Engineering

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