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.

Jobs

Quick Undrained Shearbox Test

Quick Undrained Shearbox Test

(OP)
As far as I understand a shearbox test is a drained test(assumption that excess pore pressure is 0).
I do however have clients who require "quick undrained" tests on partially saturated soils.
This can surely, at best, be a total stress test?
Any recommendations on how quickly I should shear the samples? But more importantly:
How do you interpret the test data?

RE: Quick Undrained Shearbox Test

Sounds like something to avoid unless the client can tell you which ASTM standard to follow (and I don't think there is one). In a typical shear box, I don't think you can shear it fast enough to actually be fully undrained, and how would you know if you had? Maybe if you had a hydraulic actuator that could shear it to failure in just a few seconds, instead of a typical mechanical drive? If the client is the engineer, get him to explain exactly how to do the test, charge your hourly rate for the nonstandard work and writing the disclaimer, and let him (or her) interpret the raw data.

There are DSS machines that simulate undrained tests by adjusting the normal force to keep the sample at constant volume, but that's for saturated samples where undrained means essentially constant volume. With partially saturated soil, undrained doesn't mean constant volume, because air is so much more compressible than water.

Thought-provoking question, if nothing else. Is this for stability of embankment slopes under construction?

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


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