×
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

Improving bearing capacity with geogrid

Improving bearing capacity with geogrid

Improving bearing capacity with geogrid

(OP)
We are using geogrid layers in approx. 5' of gravel fill (remote site location)over soft silt with moisture content in 35-40% range.  Looking for computational technique or software to help quantify bearing capacity increase.  Does anyone have a recommendation?  We estimate capacity of native material in the 200 psf range and would like to reach 1000 psf at bottom foundation.

RE: Improving bearing capacity with geogrid

One thing to keep in mind is that even if you have the "bearing capacity" aspects covered due to the geogrids, you will still have settlements due to your pad construction - on very soft clays, this might be relatively substantial.  Have you checked out the literature of Tenex? I know it is for roads, but you might get a start there.  There were/are a number of papers in the ASCE journals that I remember - but offhand, don't know the correct refs.  Will think about this more.

RE: Improving bearing capacity with geogrid

Contact your local Tensar Earth Technologies, Inc.  representative.  You can get their design program SpectraPave2.
www.tensarcorp.com

RE: Improving bearing capacity with geogrid

Why do you need geogrid when you are using 5 ft of gravel. What is the depth of influence of your footing.You need to look at this aspect before looking at geogrids.

RE: Improving bearing capacity with geogrid

You can take in-situ undisturbed samples of the silt just below the gravel and run direct shear or triaxial and use the c-phi to comput allowable bearing pressure. Then you can work backwards and assign a bearing pressure on top of the gravel, so you won't exceed the computed bearing of the silt.  I suspect settlement will control, specially if the compressible silt thickness is more than the gravel cover.  

A Member of
www.civilvillage.com

RE: Improving bearing capacity with geogrid

I agree with fndn, once the bearing capacity of silt is in hand, one can assign the required-thickness of gravel which is used for distributing the pressure to the silt. And I guess the bearing capacity won't be a problem (If it is a problem then one may think to use geogrid); The possible settlement is a matter that is needed to consider.

RE: Improving bearing capacity with geogrid

Geogrid is good for limiting differential settlement if used properly.  There will still be total settlement issues.  Depending on how it is utilized (usually 3 to 5 layers) total settlement can be limited by up to 60%.

Tensar can provide engineering guidance.

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