Strap Beams for Pile Caps Near Property Line
Strap Beams for Pile Caps Near Property Line
(OP)
Hi,
Does anyone know of any good resources for this? I feel like this is different than a traditional strap footing.
Thanks,
Matt, EIT
Does anyone know of any good resources for this? I feel like this is different than a traditional strap footing.
Thanks,
Matt, EIT






RE: Strap Beams for Pile Caps Near Property Line
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RE: Strap Beams for Pile Caps Near Property Line
...there would be some shear as a result of the cantilever action (causing some uplift at interior column), but I don't think that will have a huge influence on my design.
RE: Strap Beams for Pile Caps Near Property Line
RE: Strap Beams for Pile Caps Near Property Line
I tend to agree with you. There are plenty of examples for common strut and ties applications (e.g., deep beams, corbels, etc.) but not really any for pile cap strap beams. For the d-region (which I agree with you is really only the cantilevered portion), do I require the minimum horizontal and vertical shear reinforcement as required by ACI? I think this is uncommon in pile caps. Also, for the node above the pile, how do I determine the width of that... that is would it be governed by the width of the beam, the width of the pile cap, or the width of the piles themselves? Thanks for the input.
-Matt, EIT
RE: Strap Beams for Pile Caps Near Property Line
But I think your situation is a bit different (IIRC your problem from the other thread you posted on this) as you are trying to restrain the rotation of the tip of a single pile by connecting it to the cap of another pile group. That sort of problem screams some sort for FEA or some other computer solution because when modeling the rotational stiffness of the pile group on the far end, the contribution will be influenced by localized affects and won’t lend itself to a simple model (like a single free head pile).
Also (another reason for the computer solution is the fact that you may want to consider some differential settlement (and its influence on the forces in the strap; I typically have). Granted settlement in piles tends to be low, but I’ve never gone without superimposing those forces on my other results.
And I'd forget about the deep beam stuff.....the distance from cap to cap (relative to the "d" of the strap probably precludes it anyway.
RE: Strap Beams for Pile Caps Near Property Line
I see no reason for a fancy FEA of this as WARose suggested.
RE: Strap Beams for Pile Caps Near Property Line
Without seeing a layout of the thing that’s difficult to say. I can think of some scenarios where it wouldn’t…..others where it would be. If (for example) a row of piles were not directly under the strap, the (flexural) stiffness of the cap would play a role in the forces developed and their distribution (this doesn’t lend itself to a simple model). In the scenario of settlement, the afore mentioned layout could potentially relieve some forces in the strap. The possibilities are endless.
I just mention that from my standpoint as I could set that up (in STAAD) very quickly. (In fact, just about as fast as I could do the hand calculations.) But, to each his own.
RE: Strap Beams for Pile Caps Near Property Line
-Matt, EIT