×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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

Subgrade reaction coefficient for piles using japanese design code for building foundations

Subgrade reaction coefficient for piles using japanese design code for building foundations

Subgrade reaction coefficient for piles using japanese design code for building foundations

(OP)
Hi All,

I am using LPile to derive p-y curves for a pile. I am also cross checking these springs using an empirical method, which I think is based on the "Japanese design code for building foundations, (AIJ, 2001)" - unfortunately this is only available in japanese.

The empirical equation I am using is based on the SPT N value and the pile diameter:
kc = 56 x N x (100 x D0)^-3/4

Unfortunately the empirical method is giving me a much different pile spring to the one I obtain using Lpile. I have tried to research the basis of the empirical equation to see if I could determine why the results would be so much different, however have not had much luck (with it being in Japanese).

Any chance anyone else is familiar with this? I am using the Reece method to determine springs in Lpile,

Thanks,

RE: Subgrade reaction coefficient for piles using japanese design code for building foundations

Could you link me the code please?

RE: Subgrade reaction coefficient for piles using japanese design code for building foundations

Why not just use another english/US based method to check? Also, I would trust Lpile far more than a japanese design code. Not saying that it would not be correct, but Lpile (and the methods employed) are industry standard now.

RE: Subgrade reaction coefficient for piles using japanese design code for building foundations

What is the kc value? and what is the restraint at the top of the pile. The latter value has a real impact on the output.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

RE: Subgrade reaction coefficient for piles using japanese design code for building foundations

(OP)
Hi CovertShear - the code is listed here: https://www.aij.or.jp/eng/publish/wwwpub.htm (7th one down in the structural engineering section) - I don't have a soft copy sorry.

EireChch - this approach is referenced in a New Zealand based code/report (Research Report 553) - I use Lpile also, was trying to see why the difference in springs using this method and Lpile would be so different - more for my own learning.

Dik - at the moment, we are modelling both piles with a free head - but I'm not sure what fixitiy the Japanese Code is assuming. kc gets multiplied by pile diameter and spring spacing (vertical spacing in model) to obtain the soil spring softness.

Thanks All

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