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

Hollow Stem Auger versus Mud Rotary (Beach Sand)

Hollow Stem Auger versus Mud Rotary (Beach Sand)

Hollow Stem Auger versus Mud Rotary (Beach Sand)

When should Hollow Stem Auger (HSA)/Standard Penetration Test (SPT) borings not be utilized?
Recently, I was provided soil test borings (logs) performed a few hundred yards from the beach and HSA/SPT was performed. Groundwater was at 4-ft in SP classified sands. The N-values did not appear unreasonable, however, I would think Mud Rotary would be preferred. Just looking for clear guidance on whether HSA/Split Spoon techniques in this type of environment is considered reasonable......as obviously, it
can be done.

RE: Hollow Stem Auger versus Mud Rotary (Beach Sand)

We wouldn't use HSA drilling for much deeper than 5 or 10 ft below the water table. It's all about controlling heaving (saturated) sand. Our drillers must be able to convert to mud if they get heave that they can't control within one sample. We'd require a field geologist or engineer be on hand to document such matters. Typically; however, we'd just use mud in the Coastal Plain.

Clearly there are two problems: Heave from gradient and heave from auger movement. A 2-1/4-in HSA has a 6-1/4-in outside diameter. Each time you break the augers, they drop - even when using the auger fork. A 1-in drop can (mathematically) cause multiple inches of heave. Both problems are addressed in mud rotary.


ípapß gordo ainÆt no madre flaca!

RE: Hollow Stem Auger versus Mud Rotary (Beach Sand)

Agree with f-d.... mud in coastal plains

RE: Hollow Stem Auger versus Mud Rotary (Beach Sand)

Agree with fatdad preferred method for liquefaction assessment of saturated loose sands.

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


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