Contact US

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!

*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

Transmission Structure Pier Foundation - Circular Ties

Transmission Structure Pier Foundation - Circular Ties

Transmission Structure Pier Foundation - Circular Ties

For pier foundations of transmission line, what is the ties spec everyone is using? My company uses the standard below. I just want to ask those on this forum who are far more experienced than me about this and why this seems to differ from other foundation designs I've seenby people who have been in the industry for years.

For the longest time we've had our circular tie overlap length follow ACI even though ACI does not really address pier reinforcement per ACI 1.1.6


Where longitudinal bars are located around the perimeter of a circle, a complete circular tie shall be permitted. The ends of the circular tie shall overlap by not less than 6in and terminate with standard hooks that engage a longitudinal column bar. Overlaps at ends of adjacent circular ties shall be staggered around the perimeter enclosing the longitudinal bars.

We've been told we must use ACI chapter 12 for tension development length to calculate that circular overlap length properly and then add in hooks. But really the requirement for foundations including drilled shaft is found in the IBC Chap 18 for deep foundations. Except for seismic applications, longitudinal reinforcement is required in shafts that are subject to moments, and only in the portion of the shaft where the moment exceeds the cracking moment as defined in Chapter 18. When longitudinal reinforcement is required, it must be tied together with transverse ties or spirals. Except for seismic applications, where specific requirements must be applied, the transverse reinforcement is constructibility reinforcement and does not need to meet ACI requirements for compression members transverse reinforcement.

RE: Transmission Structure Pier Foundation - Circular Ties

I don't know much about foundations. I do the above ground steel design for towers and poles and substation structures. I believe our foundation engineer uses LPILE or MFAD to do the drilled pier design. Back in the ancient days, we used a program called beam-column to design the piers. If you are a PLS-CADD user, there is a Caisson program they have available but I don't know if it does the reinforcing bar design.

I have been called "A storehouse of worthless information" many times.

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close