×
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!

*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

Designing Key for a concrete retaining wall
3

Designing Key for a concrete retaining wall

Designing Key for a concrete retaining wall

(OP)
I am designing the Key for a concrete retaining wall based on Passive lateral force as per below sketch:



Is that right?

But what about the active lateral force produced by soil above heel at ground surface?
How can I be sure that this force will not detach the key from the base as I am not including it in designing the Key?



Replies continue below

Recommended for you

RE: Designing Key for a concrete retaining wall

The state of soil under tail slab is uncertain, thus it is usually conservatively ignored. Note that the critical shear plane is at the interface of base slab and soil, and the design shear force of the key equal to the sum of horizontal forces minus the sum of vertical forces times friction coefficient. Both forces (H & V) are calculated with respect to the critical shear plane.

RE: Designing Key for a concrete retaining wall

The passive force will be far in excess of the active, and would reduce the overall design load if you were to account for it. So in my opinion, if you are designing the key as a cantilevered beam with only the passive pressure, then you're being conservative but correct. That is how I would design it as well.

RE: Designing Key for a concrete retaining wall

(OP)
@retired13

The design shear of the key should not be equal to the cyan area mentioned in the below photo?

RE: Designing Key for a concrete retaining wall

I think the sketch was not drawn to-scale, the cyan area seems to indicate that, if the development length exceeds the preliminary key length (selected to satisfy force equilibrium), than you have to extend the key to ensure adequate bar development length. By doing so, you will need to re-calculate the passive force with reference to the new key base (bottom of the cyan block). I don't think it is a good way to handle this situation, rather, you shall try select a smaller bar with closer spacing, thus As remains the same with shorter Ld requirement. Make sense?

RE: Designing Key for a concrete retaining wall

(OP)
@retired13:

it is very clear now, thank you all a lot.

RE: Designing Key for a concrete retaining wall

2
You are welcome.

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



News


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