×
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

Geotechnical Mohr Circle

Geotechnical Mohr Circle

Geotechnical Mohr Circle

(OP)
Hi I am trying to develop Mohr circle.  I Have deviator stress which is (sigma 1 - sigma 2)/2.  I also have three confining pressures for one sample.  Can someone tell me whether confining pressure is sigma 1 or sigma 3?

RE: Geotechnical Mohr Circle

sigma 3 is ususally termed as the confining pressure in the test cell.  The deviator stress being the stress applied over and above sigma 3.

Andy Machon

 
 

RE: Geotechnical Mohr Circle

In a triaxial test the hydraulic pressure in the cell is the confining pressure sigma 3.
Sigma 2 is the same as sigma 3 in atriaxial cell.
Sigma 1 is increased above sigma 3 by applying a 'deviator' stress in the vertical (axial) direction by loading the top of the sample.
Sigma 1 - Sigma 3 is the deviator stress.

(Sigma 1 - Sigma 3)/2, half the deviator stress, is the radius of Mohr's Circle and if Sigma 1 is the deviator stress at failure it is the shear strength.

In an unconfined test, Sigma 3 is zero so the shear strength is half the uniaxial compressive strength.

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