×
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

Shear key design for base slab to resist uplift in caisson
2

Shear key design for base slab to resist uplift in caisson

Shear key design for base slab to resist uplift in caisson

(OP)
To resist the hydraulic uplift for a caisson, I thought of providing shear pockets (say 400x400x75mm) on the caisson walls at 1m centres horizontally so that the base wall can be cast into the shear pockets which would give good shear capacity against the uplift. Also, I was thinking to provide some dowel bars within the shear pockets.What will be the design for this dowels? Can anyone help on this?
 

RE: Shear key design for base slab to resist uplift in caisson

Please provide a sketch to clarify your design intent.

RE: Shear key design for base slab to resist uplift in caisson

Interesting idea- How would this be constructed? I gather someone would need to drop into the caisson to hand dig these shear pockets and tie the rebar

RE: Shear key design for base slab to resist uplift in caisson

(OP)
While casting, polystyrene will be placed at the pockets which can be removed later to form the shear pockets. There will be a concrete plug to stop the water. People can go down and weld the dowels to the caisson reinforcement.

RE: Shear key design for base slab to resist uplift in caisson

Well, lacking the sketch, one can muse that the design of dowels crossing the interface between concrete in the caisson and concrete in the plug should be dimensioned according to shear-friction principles, or, more classically as single groups of inclined rebar against shear. Strut and tie schemes can also be brought to usefulness... so one must ensure a maximum shear stress is respected as limited by shear strength of the concrete, compression strut maximum stress and tie recommended maximum stress.

Once the shear in the concrete is approaching its ultimate value, the strut and tie scheme will be representing the situation, in spite of the fact that at lower solicitations and on the key action the steel may not be much stressed.

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