ACI 318 General Questions
ACI 318 General Questions
(OP)
Hello Guys
1) I am designing according to the ACI code, but I would like to follow the IBC for earthquake zone design instead of ASCE, so my question if I do so which load combinations I should pick, the one based on IBC,or the one based on ASCE(the same as ACI) to make results consistent or it doesn’t matter!!!!
2) I can found in ACI calculation the deflection based on I effective for beams and one way slab, so for two way slab ,where is the reference?
3) They is one statement said that third of flexure reinforcement for T beam can be distributed in b effective and the rest will be in bw( can anyone reference the clause in ACI318-11),I can’t find it!!!
4)0ne important thing is the ACI code is using three words (hoops, stirrups, seismic stirrups),for hoops I found one details in in ACI code for intermediate sway, but what the difference with others
5 Clause 11.2.1.2 Calculate Vc for axial member, so what about combined moment and axial Vc
1) I am designing according to the ACI code, but I would like to follow the IBC for earthquake zone design instead of ASCE, so my question if I do so which load combinations I should pick, the one based on IBC,or the one based on ASCE(the same as ACI) to make results consistent or it doesn’t matter!!!!
2) I can found in ACI calculation the deflection based on I effective for beams and one way slab, so for two way slab ,where is the reference?
3) They is one statement said that third of flexure reinforcement for T beam can be distributed in b effective and the rest will be in bw( can anyone reference the clause in ACI318-11),I can’t find it!!!
4)0ne important thing is the ACI code is using three words (hoops, stirrups, seismic stirrups),for hoops I found one details in in ACI code for intermediate sway, but what the difference with others
5 Clause 11.2.1.2 Calculate Vc for axial member, so what about combined moment and axial Vc






RE: ACI 318 General Questions
1. The IBC refers to ASCE 7 so they should be generally compatible. If they are not - the IBC would generally alter or amend the ASCE 7 spec a bit.
2. There is nothing direct in ACI 318 for two-way deflections other than a table that limits how thin you can go (Chapter 13).
3. I think it is in chapter 10. If not then chapter 7 but I'm away from my office so can't look it up.
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RE: ACI 318 General Questions
any calcification for point 4 and 5
RE: ACI 318 General Questions
Keep in mind that when you say "The ACI Code" now, it makes quite a lot of difference WHICH version you mean.
For instance ACI 318-14 is quite distinct from ACI 318-11 - or indeed, every other edition of the code previous to it.
RE: ACI 318 General Questions
RE: ACI 318 General Questions
If you're talking lateral deflection, you can use ACI 318-11 10.10.4.1 (0.25 I_gross). That clause references "Flat plates and slabs" and does not distinguish between one and two way systems. I don't know of a code specified effective "I" for vertical deflections.
ACI 318-11 10.6.6 is the only related clause that I'm familiar with.
If you reference specific clauses where these terms are used, we can probably parse out the meaning. In general:
1)Hoops - transverse reinforcing encompassing the entire member and most often used for longitudinal bar buckling prevention.
2)Stirrup - transverse reinforcement that may or may not wrap the entire cross section and are used to resist shear.
3)Seismic stirrups - same as #2 but with 135 degree seismic hooks at the stirrup leg anchorages that perform better than 90 degree hooks when exposed to significant plastic deformation.
See ACI 318-11 11.2.2.2.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: ACI 318 General Questions