Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Seismic analysis of piles

Status
Not open for further replies.

HACHEMM

Structural
Apr 16, 2024
2
Hello, i am analyzing a 13 story building sitting on a piled raft foundation.
The problem occurs when performing a seismic analysis for the piles. The geotechnical company provided us with two different stiffnesses for the piles to be used (one for compression and one for tension).
When performing the analysis, some piles will be compressed and some will be tensioned due to the EQ direction.
Please if someone is able to help, what could be the way to input both stiffnesses in the analysis so the software automatically generate forces depending on the state of the pile.
I tried to use a multilinear link and then assign it later to a point spring, but i am having a trouble in the definition of the back bone curve of the link, is it considered as a scaling curve for the effective stiffness that should be input, or it should have a normal values a normal force value whatever will be VS disp?
And what could be exactly the definition of the effective stiffness of a multilinear elastic link?
I am using ETABS.
Thank you very much!!
 
 https://files.engineering.com/getfile.aspx?folder=c9550337-65bd-4850-a150-9f571c58aac6&file=Screenshot_2024-04-16_232309.png
Replies continue below

Recommended for you

What's the issue with the backbone curve of the multilinear link? The units are in defined on the input form.

image1_j0qtgn.png


I just tried on my end and it seems to be working well. 1 kip of force is yielding 20 inches of displacement in tension and 1 kip of compression is yielding 1inch of negative displacement.

image2_ljf79h.png


image_3_dnsr8a.png





S&T
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor