318-14 Retaining Wall steel details, Minimum reinforcement, Cut off points.

[sswan60]

I'm looking for a few references in 318-14 that I used to follow for retaining walls in older versions of the code. I realize the code has gone to a more member specific layout but I would think these items would still pertain. My application is a cantilevered retaining wall.

1. Minimum reinforcement. This used to be in 10.5. How does the 318-14 reference these requirements for walls?

2. Vertical tension steel cut off. Old 318 12.10.3 required steel extend d or 12db past where not needed.

I can find these items in 318-14 for beams and slabs but not walls. My application is clearly a wall so I would think Ch. 11 would either spell it out or reference it somewhere else in the code.

thank you

 

[TehMightyEngineer]

ACI has a free transition key document that lets you find where the sections moved between ACI 318-11 and 318-14:

https://www.concrete.org/store/productdetail.aspx?ItemID=318T1114&Format=DOWNLOAD&Language=English

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[sswan60]

Yes, Thanks.
I'm familiar with that reference. When I use it it sends me to either Beams or Slabs in 318-14. I'm trying to find if or how the 14 code requires it for walls.

 

[TehMightyEngineer]

If I had to guess I suspect ACI 318 is trying to avoid explicitly stating what you have to do and leaving it up to engineering judgement. For design of cantilevered retaining walls, ACI 318-14 section 11.1.4 has you reference 22.2 through 22.4, and 11.6 for minimum steel; that's it.

I'd say if you're looking for explicit steps of what design checks need to be made I suspect you'll find none. I'd reference the ACI provisions for beams and one-way slabs and the CRSI design guide on cantilevered retaining walls, then design as you've always done. The 2014 CRSI cantilever retaining wall design guide references ACI 318-14 and they also use all the typical provisions from the various beam/slab sections of ACI 318-14.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[sswan60]

>The 2014 CRSI cantilever retaining wall design guide references ACI 318-14 and they also use all the typical provisions from the various beam/slab sections of ACI 318-14.

OK, good to know. Thanks