×
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

Help - coefficient of earth pressure at rest
2

Help - coefficient of earth pressure at rest

Help - coefficient of earth pressure at rest

(OP)
This is a theoretical question but it is related to a potential problem with a deep outfall shaft which subject to large intermitant internal pressures.

If I drill a borehole say 30m deep in sands and gravels overlain by boulder clay. Install a packer at the base of the borehole and expand the packer, will the coefficient of earth pressure at rest (Ko)value increase or will it remain at Ko = 1-sin angle of friction.

My thinking is that it will increase until it reaches the Kp value just before shearing.

Put it another way - is there any way you can increase the Ko value of a granular material insitu.

RE: Help - coefficient of earth pressure at rest

(OP)
THanks fndn. I have concluded from the USACE publication "Design of Piling Foundations" that the effect of driving a pile results in increasing the K value, which has confirmed my assumption.

It is now my intention to increase the K value of the Glacial sands and gravels by TaM grouting around the shaft from approx 20m to 30mbgl.  The inrease in the K value of the soil and will reduce radial expansion of the shaft to an acceptable level.

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