×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

(OP)
I need help identifying what the minimum transverse reinforcement ratio is for a 12-inch diameter drilled pile. fc=6000psi fy=60000psi. The 2007 California Building Code section 1810A references ACI 318 21.4.4.1-3. Section 21.4.4.1 says that the minimum transverse reinforcement ratio is given by the equation r=0.12*fc/fy. This gives me a reasonable result. There is a comment below that equation that references ACI 318 eq. 10.5 which is for columns. My question is which equation governs. If I use ACI 318 eq. 10.5 the required transverse reinforcement gets a bit out of hand requiring a #5 spiral at 3-inch pitch.  I know that designing from the gut is not the best idea but I have seen quite a few pile cages go in the ground with much smaller spiral steel at a greater pitch. Any help on this would be much appreciated.

RE: Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

For one thing, ACI 318 doesn't apply to piers/piles.  Check out ACI 336, found here:  ACI 336 link

The only place you'd use 318 is in the top of the "pier" where it comes out of the ground and is essentially a short column, - in those areas the typical column tie requirements would control.

For the in-ground piers, ties can be less intense.

 

RE: Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

JAE,
The 2006 IBC has similar requirements to the CBC.See section 1810.1.2.2 for cast-in-place pile reinforcement requirements in SDC D thru F. This section references ACI 318-05.

RE: Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

I think it is chapter 1 or 2 in 318 where they specifically exclude piers from 318.  I'm not sure why the CBC would back reference 318 for piers.

 

RE: Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

(OP)
Thank you all for the replys.  This was very helpful.

RE: Minimum Transverse Reinforcement Ratio For Cast In place Concrete Pile

Did I miss the answer to the question? Not familiar with IBC or CBC...

For 12 and 16 inch piles, I typically use a single 15M bar (#5) by 6m long (approx 19')

Dik

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources