BASIC WIND SPEED CALCULATION

Dear All,

As per project specification " The basic 10 minute mean wind velocity (Vb) used for design shall be 35 m/s."

We used ASCE#7 in that entered basic wind speed is 35000 mm/sec

Comment:: As already clarified, 35 m/s is the basic 10 minute mean wind velocity (Vb) used for design. However, to apply wind speed as per ASCE 7. You need to apply necessary conversion factor to convert this speed to 3 sec. gust speed.

Please tell me how to convert this ?? and get the actual basic wind speed in ASCE#7.

Please see Durst curve, FIGURE C26.5-1 Maximum Speed Averaged over t s to Hourly Mean Speed, ASCE 7-10.

Thanks Mariag.

I observed 35 m/s is the basic 10 minute mean wind velocity (Vb)this is in Euro code.

From your help:

I checked FIGURE C26.5-1

for entering in ASCE#7

we require for 3 sec gust speed.

so,

for 3 sec (in x- axis) gust duration -->

Vt/V3600 = 1.5 ( from y-axis of the graph)


Vt= 35 m/sec @ 10 min (as per project spec)


==> 35/V3600 = 1.5

V3600= 23.33 m/sec @ Averaged over 1 hr

But what value I have to enter in ASCE#7 - Basic wind speed??

Please clarify

Durga,

You may read in graph the value corresponding to V_3sec/V_3600, then read the value corresponding to V_600sec/V_3600. The ratio of these values is V_3sec/V_600. Multiply your basic value v_600=35 m/s with the number representing V_3sec/V_600 and you got the basic value of V_3sec as input in ASCE 7.

Thank you Mariog