Need a book? Engineering books recommendations...
Return to index: [Subject] [Thread] [Date] [Author]
RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
[Subject Prev][Subject Next][Thread Prev][Thread Next] To: <seaint(nospamat)seaint.org>
 Subject: RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
 From: "Bruce Holcomb" <bholcomb(nospamat)brpae.com>
 Date: Wed, 4 Oct 2006 08:31:40 0500
I’d like to see your PDF. I don’t know if I can be of any assistance, but I have considered the top steel in resisting anchor rod pullout. I don’t have a complete answer, or even a good partial answer, but if you have a plain concrete footing and a footing with top steel, it seems pretty obvious that the footing with top steel with have greater pullout resistance. I’ve considered shear friction and simply the rebar steel shear strength (0.4*Fy). I think there is a factor to account for the rebar in the ACI design method, but I don’t recall right now.
BDH
From: Haan, Scott M
POA [mailto:Scott.M.Haan(nospamat)poa02.usace.army.mil]
Can you use horizontal reinforcement in the top of a footing to resist the pop out of a concrete tiedown anchor rod? I talked about this idea with an intelligent engineer and he said it can't be done.
I drew a free body diagram of a pop out cone with the reinforcement developed in the cone and with the shear friction parallel to the cracks with the vertical of shear friction component cancelling out the upward force and the horizontal component cancelling out. I'll email a .pdf of the solution if someone wants to look at it and tell me where it goes South.
He said the tension is acting vertically across the inclined crack failure plane, and you've got the shear component parallel to the crack and tension component perpendicular to the crack, and that the shear friction formula in ACI 318 for reinforcement at an angle to the crack only applies to force component parallel to the crack.
I don't believe horizontal reinforcement couldn't clamp concrete from popping out with enough horizontal reinforcement clamping the pieces together.

 FollowUps:
 Prev by Subject: RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
 Next by Subject: RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
 Previous by thread: RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
 Next by thread: RE: shear friction from horizontal top reinforcement, to resist holdown anchor pop out in A footing?
 About this archive
 Messages sorted by: [Subject][Thread][Author][Date]