Hairpin in Pre-engineered Building Foundation
Hairpin in Pre-engineered Building Foundation
(OP)
Could you please shed some lights on where I could find the design guidelines for design of hairpins in pre-engineered building foundation?
Thanks.
Thanks.






RE: Hairpin in Pre-engineered Building Foundation
The total lateral force is resisted in shear at the cup of the Vee at the anchor bolts. Call that total lateral kick "H". Each leg of the hairpin takes one half of that total force multiplied by the ratio of the incline of the haipin leg. The greater the spread of the hairpin, the greater the force in the rods to resist "H". Then you just have to make sure you have enough length in the legs to develop the force. Simple really.
Mike McCann
MMC Engineering
RE: Hairpin in Pre-engineered Building Foundation
RE: Hairpin in Pre-engineered Building Foundation
RE: Hairpin in Pre-engineered Building Foundation
I am well aware of your concerns and agree, but have used these slabs on the ground for many years to embed the hairpins. Generally, they extend less than 8 feet into the slab proper from the mainframe anchor bolts. I also spec WWM which (1) extends the amount of slab you are picking up in dead load, and (2) provides continuity between the hairpins in case one is cut. I would have a problem though if the owner wanted to use fibermesh in lieu of the WWM.
Remember though that one of the driving forces in the footing sizes is the uplift. If you make the footing deeper rather than larger to add the extra weight required to resist the uplift, then you get the added benefit of lateral bearing against the footing to help resist the spreading. I never rely on this force unless the owner does not want a slab or tie beam installed, but know it is there as a redundancy in case any hairpin is cut.
Mike McCann
MMC Engineering
RE: Hairpin in Pre-engineered Building Foundation
RE: Hairpin in Pre-engineered Building Foundation
Mike McCann
MMC Engineering