Wind speed for lebanon

[sebfr1138]

Hello

I need to find Wind for Lebanon. It is for a wide art piece so usualy, i use wind speed from building design standards

I find building standard for lebanon name wich is "Calculation of wind loads on structures NL 137:2017"

but I have no answer writing to Libnor, the lebanese standards organisation. And no way to buy it online too.

i mostly need wind gust speed.


thanks a lot

Sébastien

 

[ThomasH]

Hello
Out of curiosity I tried Google with "Design Wind Speed Lebanon" and found this:

http://www.undp.org.lb/communication/publications/downloads/National_Wind_Atlas_report.pdf

I don't know it is helps you, I have not read it in detail, but it seems to be wind data. The purpose is wind power and the data is from a study be the UN.
Another possibility is this.

https://globalwindatlas.info/area/Lebanon

Good Luck
Thomas

 

[sebfr1138]

Hello and thanks for your answer

unfortunatly, i have already read this documents and visit this web site. there are "hundreds" of reference about wind power and wind density in lebanon, but nowhere, i was able to find some values about wind gust or extreme wind. I know i may miss it somewhere but i really explore first few pages of google with various search words.

thanks anyways and have a nice day

Sébastien

 

[GeorgeTheCivilEngineer]

Does the Eurocode map go as far as Lebanon? BS EN 1991-1-4 I think.

 

[sebfr1138]

in fact, before lebanese standard NL 137:2017, it s seem that you can use BS, eurocode or asme standard to do building computation

but no way to find the reference value for wind speed in lebanon.

eurocode goes up to Greece and ciprius

https://www.dlubal.com

work for isreal too but not lebanon...

 

[ThomasH]

Hello

If you can find the wind speed for Israel, isn't that a good reference value? They should not differ a lot if the other parameters are the same.

When you have done your design, is there any local authority that will check the calculations? If there is, try to contact them for information if possible. It there isn't, I would use data from for example Israel, use a margin of safety and calculate the wind load.

What code are you using for the remaining design? One thing tat is important regarding codes is to be consistent. All codes not neccessarily have the same safety approach.

Thomas

 

[sebfr1138]

Hello

Thanks for your interest ThomasH

in fact, i design a middle size piece of art (3m high) and i don't know where it will take place in lebanon, but probably on the top of a roof

Generaly, i use a 1.5 safety coeficient between wind gust speed loads and elastic limit of the material. it s really not a building and most of the différents standards are not applicable in my cases

in high winds areas, i take care of fatigue limit of matérials too

Sébastien

 

[ThomasH]

Hello
But how do you go from the wind speed to the actual load? There has to be some kind of established model for that.

I have also designed artwork for wind and I used Eurocode for that. The challenge was the shape factor, not the windload.

Thomas

 

[sebfr1138]

As I am aerospace engineer so, aerodynamics is not a problem.

i use Cx of basic shape (like sphere or plate plane) and thats it fit well with artwork i work with

Fx = 1/2 ro V^2 S Cx

in most case, i know that the real drag will be less than plane plate so i am conservative

Sébastien

 

[rb1957]

are you certifying the design to some standard ? If not clear from online references, talk to the standards people.

if "just" for design, pick a number (typical of nearby areas), add a factor, and state "good for gusts up to Xmph/kph/knts"


another day in paradise, or is paradise one day closer ?

 

[sebfr1138]

In Art, there are no standard, that s why, i use a coherent wind speed from building standard and demonstrate that with such wind, it will be OK. the scale is not the same that building, but if pièce of art fall, it could injure people anyways

we try to make it last for years, and because the external surface need to stay perfect for years, we choose very durable materials


that problem is that wind gust could be very different through the world. already in France, it could vary a lot, so sizing structure could vary a lot too

 

[rb1957]

I get it, I think you're looking down a very deep hole ! when you say "gust" what duration ?

I'd design for a gust speed, maybe 100 mph (or 160kph) as a nice round number. Once winds like this are happening there are all kinds of other effects ("missiles") that'll impact the survivability of the structure.

another day in paradise, or is paradise one day closer ?

 

[phamENG]

but if pièce of art fall, it could injure people anyways

Which is precisely why these are treated as building elements in the US. They still have to meet the building code. The code has special sections for 'non-building structures' and 'building appurtenances'. In most cases, the smaller size drives higher net wind load per unit area for the design requirements due to the statistical variation in peak wind load over a given area.

 

[ThomasH]

Hello again,
If you know aerodynamics you should be okey with the wind load.

As for your statement that there are no applicable standards. Based on my own experience, many "building" codes are applicable beyond just buildings. The artwork I have designed could be considerad as a steel structure and that made Eurocode suitable for the design. But it also depends on where in the world you are geografically. In my experience, countries that previously used British Standard now often use Eurocode.

Hopefully you figure it out and manage to convince the authorities if there are any to convince.

Edit: I just thought of something. You have only asked about wind loads. Do you have data for other possible loads applicable in Lebanon?

Thomas