Need a book? Engineering books recommendations...
Torsion Reinforcing Question[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: "Seaint" <seaint(--nospam--at)seaint.org>
- Subject: Torsion Reinforcing Question
- From: "PEC - Lake City" <pec(--nospam--at)isgroup.net>
- Date: Mon, 20 Nov 2000 16:27:06 -0500
Even though it starts out sounding like it, this is not just for the bridge folks ..... I'm reviewing a contractor's proposed modification (prepared by and signed and sealed by a properly licensed professional engineer) to an intermediate bent for a AASHTO girder bridge. The modifications are needed because one of the piles was driven out of tolerance about 6" transversely to the bent. The offset creates torsion in the bent cap and additional moment in the pile, but it is the torsion I have a question about. As originally designed, the bent cap was 48" wide and double shear stirrups were detailed. The closed stirrups were 34" wide, so that each pair has 4 "legs": one stirrup has a leg 3" clear of one face and another leg 7" clear of the other face. The companion stirrup is a mirror image. The contractor proposed to widen the cap 4" to accommodate the out-of-tolerance pile and wants to "spread" the existing stirrups to avoid having to fabricate new stirrups. I plan on rejecting the re-use of these stirrups since they have 90 degree stirrup hooks rather than 135 degree stirrup hooks and therefore cannot be considered effective for torsion. However, my main question is this: Do stirrups used for torsion have to be closed perimeter stirrups? Are paired stirrups (similar to what was originally designed) acceptable? If so, it seems that there would have to be some minimum overlap distance required. ACI 318-95 R220.127.116.11 discusses stirrups with lap splices, but this is really a different case. TIA, David Finley, P.E.
- Prev by Subject: Re: Timber frame house design - advice
- Next by Subject: Troll [Was: please reply to test]
- Previous by thread: RE: SAP2k: Modeling concrete floors with monolithic conc. beams
- Next by thread: Online Professional Development Hours