×
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

Dissipation of Axial Load in Continuous Waler

Dissipation of Axial Load in Continuous Waler

Dissipation of Axial Load in Continuous Waler

(OP)
I am looking for a good reference on how to model the dissipation of the axial load in the wale into the wall of a rectangular earth retaining system.  Thank you in advance for your help.

RE: Dissipation of Axial Load in Continuous Waler

awatka,

Not sure what exactly you mean.

The axial load is usually assumed to be opposed on opposite ends of the excavation.

RE: Dissipation of Axial Load in Continuous Waler

(OP)
On deep excavations, the waler is subjected to extremely high axial loads from both the opposing walers and corner braces.  ASCE Geotechnical Special Pub No. 74 (Pg. 96 - Guidelines of Engineering Practice for Braced and Tied-Back Excavation) verifies this by stating "Because combined bending-compression is critical to wale design, an important consideration is the dissipation of the axial load in the wale into the wall and thus into the retained soil."

I am trying to find out how to model this dissipation for a sheetpile wall in order to achieve the most economical wale size.  If dissipation of load is not considered, the size of the wale can become tremendously large and costly.

RE: Dissipation of Axial Load in Continuous Waler

I saw this unsuccessfully attempted once in the past.  A MAJOR collapse resulted.  I have never seen a reference on this dissipation.  I don't doubt that some load is dissipated; I just can't say how much.  Remember, the steel wale is much stiffer than the soil that may (or may not!) be surrounding the soldier beams or sheet piling.  If the wale is stiffer, it will not shed the load so easily.

www.PeirceEngineering.com

RE: Dissipation of Axial Load in Continuous Waler

I always tend to disregard this as it relies too much on friction which is not guaranteed.

RE: Dissipation of Axial Load in Continuous Waler

I agree...I believe the reference is that the waler dissipates axial load into the sheet pile and then through side friction into the soil. You would have to be very careful about your assumptions because you shouldn't consider that the sheet pile wall is always perfectly in contact with the soil and engaging it. Theoretically you could model the sheet pile wall as a shear wall abc the waler as a drag element.

Ultimately, I think the answer is that you balance the axial load with the opposing side by making the waler continuous.

RE: Dissipation of Axial Load in Continuous Waler

We always assume the axial load is dissipated into the sheetpile or soldier pile wall then into the soil.  The walers must be welded to the walls, particularly near the ends of the wales.  A free-body diagram of the wale and load path would show that the end reactions pass must pass through the welds, then into the perpendicular walls, then into the soil.  Obviously, the welds must be capable of resisting the reaction load, and the perpendicular walls are treated as if they are diaphragms.  The diaphragms must be (and usually are)stiff enough to tranfer the load.

In a one-story building subject to wind load, the wind load is transfered from the walls to the foundation at the bottom and to the roof at the top.  The roof diapragm must be stiff enough to transfer the load to the moment resisting frame.  AISC has a guide for determining the stiffeness of the roof.  Using that guide you'll find that a sheetpile wall has plenty of stiffness to accept the "dissipated" load from the wale end reaction.

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