×
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.

Students Click Here

Whether lateral load test can be allowed prior to vertical load test

Whether lateral load test can be allowed prior to vertical load test

Whether lateral load test can be allowed prior to vertical load test

(OP)
Load test (vertical & lateral) is to be carried out on same pile. Contractor wants to do the lateral load test first and then after a month will carry out vertical load test on the same pile.
Please suggest me whether this will provide a correct picture on vertical compression capacity since due to lateral load test around 4-5D of the surrounding soil will be disturbed and side friction may not generate.
How much time it will take for soil (clayey silt) to come back to its original position and regain its strength (thixotropic action).
Or do we suggest to perform the vertical load test first and then go for lateral load test.
Replies continue below

Recommended for you

RE: Whether lateral load test can be allowed prior to vertical load test

If you must test the same pile, do the vertical test first, for exactly the reasons you mentioned.  The contractor isn't thinking!  He should want you to do the vertical test first!

RE: Whether lateral load test can be allowed prior to vertical load test

Ron is right - vertical first.  Lateral test can screw up the axial load test; but the axial should not affect the lateral load test.  Er, unless you push it too far!

RE: Whether lateral load test can be allowed prior to vertical load test

(OP)
If we wait for a month or more before conducting the vertical load test, the soil may come back to its original position and regain strength. Why in that case, we cannot allow to do lateral load test prior to vertical load test?

Actually, whether any references are there where this time requirement of regaining soil strength is established? Probably, for overconsolidated soil, the gap between pile and soil continues to persist if lateral load test done first and thus shaft friction will not be generated for that part when vertical load test will be performed.Is it true?

RE: Whether lateral load test can be allowed prior to vertical load test

One question, if you are so worried about the time element between tests, why not test two piles, one for vertical and one for lateral?  That way you get both tests done in a shorter time period and can get on with the job.  The setup cost can't be much different for two piles vs one, because the setup for each test is so different.

RE: Whether lateral load test can be allowed prior to vertical load test

The 30 day delay after installation has to do with the loss of soil strength immediately adjacent to driven piles.  Clay soils are thixotropic (pronounced "thicks-o-TRO-pick" for you 'non-dirt' guys), which means they regain much of their undisturbed strength over time.  Thirty days has been found to be a good time delay before testing in order to achieve the maximum soil resistance.  (This delay should not be applied to drilled piers in most cases...)

When you run a lateral load test, you run the risk of separating a significant portion of the pier/pile from the adjacent soils.  Loss of contact means loss of axial capacity.  That's why you need to run the axial test first.


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



News


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