Wind Speed for assigning wind load. 3

[insajn]

I've read the wind rose in the city I want to design for, and I got the results of this; 61 km/hr 1 hr/year
50 km/hr 8 hr/year
38 km/hr 43 hr/year

I got the average weight of these three values and I decided to design with 43 km/hr ( the average is 40.3 km/hr exactly )

Is it ok since the 61 km/hr occurs only 1 hour a year ? btw I'm using ETABS for modeling and designing.

 

[Whoopdedo_LSU]

I don't know where you're designing for or what code. I would never design a structure using short term wind loads unless specified by code. I'd use a higher FOS if you're guessing at the load to design for and if that will control.

 

[JStephen]

Basically, you're asking if it's okay if your building only fails once per year?
In the US, the design wind speed will be specified by various building codes, based on a certain probability of not being exceeded in 50 years time.
If you're in the US, check your local building code, which likely refers to IBC, which in turn is based on ASCE 7 of various years.
If not in the US, you'd need to check your area's legal and building requirements. Maybe tell us where you're at, and some of the forum people might be familiar with requirements there.
For strength design, any of the wind loads you listed would be very very low.
They might be okay for heat loss or similar serviceability issues.

 

[insajn]

I'm using ASCE 7-10 and the building is in Istanbul

 

[structSU10]

ASCE 7 wind pressures are based on maximum wind events with large recurrance intervals (100 years plus). A single year of data does not cover the extreme cases at all. It is not a good basis to use when designing a building that will last 30,40,50 + years.

 

[insajn]

I got what you mean. Then I must design it for more thatn 61 Km/hr. This value is from Windfinder for Ataturk airport. this value has been obtained for forecasting from 2000 to this day.

This isn't a real design I'm practicing on assigning wind loads to see the behavior of the building under such loads.

Thanks for all

 

[OHIOMatt]

It looks like the US military would require facilities to be designed for 160 kph (100 mph). Though this value is based upon wind calculations of the IBC.

 

[insajn]

I have been doing it all wrong
Wind rose values are measured 10 m above the ground.

Thanks OHIOMatt

 

[insajn]

What does ASCE 7-10 Windspeeds
(3-sec peak gust in mph*) mean ?

 

[klaus.]

looks like you need some professional help....
If you design something in Istanbul (Turkey) you need to follow the local codes especially when it comes to loads





best regards
Klaus

 

[racookpe1978]

The earthquake loads in that region are going to be very severe - probably more controlling than wind loads in any realistic condition of a tower or exposed (tall) structure.

 

[JStephen]

"Given the response characteristics of the instrumentation used, the peak gust is associated with an averaging time of approximately 3 seconds."- from the Commentary in ASCE 7-05. (The older versions used "fastest mile", which gave different average wind velocities.)