Help with API650 - 3.11 - Wind load on tanks
Help with API650 - 3.11 - Wind load on tanks
(OP)
Hi,
I'm calculating a storage tank, of D=13,5m and H=10,85m.
When calculating wind load on tanks (overturning stability), section 3.11, I've followed all the steps in this section and reached the conclusion of no need for anchorage, because M<2/3x(WxD/2).
Now, I really don't know (understand) what to do with 3.11.4 that refers to sliding due to wind, and gives me a "maximum allowable sliding friction of 0,40 multiplied by the force against the tank bottom".
What am I suppose to due with this factor, where do I apply it? How do I calculate if I need anchorage because of sliding? Can anyone help me?
I'm calculating a storage tank, of D=13,5m and H=10,85m.
When calculating wind load on tanks (overturning stability), section 3.11, I've followed all the steps in this section and reached the conclusion of no need for anchorage, because M<2/3x(WxD/2).
Now, I really don't know (understand) what to do with 3.11.4 that refers to sliding due to wind, and gives me a "maximum allowable sliding friction of 0,40 multiplied by the force against the tank bottom".
What am I suppose to due with this factor, where do I apply it? How do I calculate if I need anchorage because of sliding? Can anyone help me?





RE: Help with API650 - 3.11 - Wind load on tanks
Addendum 4 to API-650 revises the wind loading considerably by adding a wind uplift requirement- you need to look into it if this tank is not specified to be built by Addendum 3.
RE: Help with API650 - 3.11 - Wind load on tanks
Can you just tell me if I should consider also 2/3.
Like this:
MaxOverturningMomentwithoutAnch.=2/3x((Wtank+Wfloor+Wroof)xD/2)
And then compare this to:
OverturningMomentfromWindPress.=Wind PressurexDxH/2
Did I understood it right?
RE: Help with API650 - 3.11 - Wind load on tanks
Your second formula would be M = pressure x D x H x H/2. But in the new Addendum 4, you have a term for uplift on the roof as well, and some additional equations to calculate uplift resistance.
RE: Help with API650 - 3.11 - Wind load on tanks
Forget the "Overturning" term I used, I'm only talking about sliding.
The overturning issue it's already taken care of, and I agree with you, I didn“t consider the floor when calculating overturning.
So:
MaxSlidingwithoutAnch.=2/3x((Wtank+Wfloor+Wroof)xD/2)
And then compare this to:
MomentfromWindPress.=Wind PressurexDxH/2
It's this what you were saying in your first answer?
RE: Help with API650 - 3.11 - Wind load on tanks
You'd have maximum sliding force = (Wtank+Wfloor+Wroof) x 0.4
And compare to Wind Pressure x D X H