Soil Structure Interaction

[adip]

Hi,All

Iam Asking about " Soil-pile interaction and modelling spring(modulus subgrade reaction) for to calculation
pile groups

regards,

Adip

 

[Focht3]

Okay, I'll bite - what's your problem? We need details...

 

[jdmm]

Focht3

You're too easy. My bet is py-curves for pile soil interaction.

jim

 

[Focht3]

jdmm - you know me too well!

BUT, he may be asking about axial behavior...

(NOT!)

 

[SoilRocks]

Hey, I bet he's looking for an easy method to develop a stiffness matrix for a bridge bent. Good Luck. I'm dying to hear though.

 

[zliazmei]

I think Adip is looking for P-Y curves.

And here is my question.

Did anybody worked with P-Y curves to model in structural software the Pile foundations?
I am recently involved in Bridge design project where the client wants the pile foundations to be added in the model using lateral soil springs.

What you think? Any coments will be verry helpful.

Thanks in Advice.

ZMEI

 

[zliazmei]

OOPS forgot.

What you mean? Now I have a geotech draft report where the values for PHI and bulk density are provided based on the geotech contractors implementations of SPT values.

I was just wondering if I use these values and REeSE procedures the results may be not verry correct. Espesialy the subgrade modulus based on Relative density.( I am working with sands and driled piles)

Think I must ask the geotech company to provide presuremeter test results. Will it be much correct? I think yes.

The problem is that if I use the results provided (mean the values for phi and density)it will remove the geotech responsibility from the geotech contractor.

Also any advice of houw to determine the relative density from provided values of Bulk density.

The code for use in the design is AASHTO.

THANKS

ZMEI

 

[adip]

Thanks,All your advice about "Soil pile interacrtion"

I have try calculation "lateral pile capacity"
with modelling spring "Hybrid method(p-y curve and winkler method)",
but can you give me examples case as consideration
(for Mr.ZMEI)


regards,
Adip

 

[zliazmei]

Refer to Florida DOT web site there are few publications regarding this method and FBPier program.

Regards

ZMEI

 

[Focht3]

Okay, jdmm, you were right. (sigh)

adip:
There are a lot of case studies in the literature - look at the reference list (that comes with the LPILE program.) I simply don't have the time - or space - to provide you with a full-blown problem example.

Are you a graduate student? Have you asked your professor or supervisor?

 

[xpert]

In practice, soil structure interaction is handled by modelling the soil as a spring system in the computer model. The Structural Engineer should not calculate these values, but require the Geotechnical Consultant to provide them.

In an onshore project, I find that it is best to ask the Geotechnical Engineer to provide "Coefficient of Subgrade Reactions in the horizontal and vertical directions", For an offshore project, Engineers are normally familiar with P-Y &Z-Y curves, which is normally provided in the Geotechnical Report.

Hope that helps.

 

[JYChen]

What is z-y curve? Are you meant to say t-z for the axial behavior?

 

[Focht3]

I'm pretty sure he meant t-z curves; if not, I'd like to know what references have used "Z-Y" curves.

Anyone interested in the subkect of pile behavior - lateral or axial - should refer to a book titled, Planning and Design of Fixed Offshore Platforms edited by Bramlette (Bram) McClelland and Michael D. (Mike) Reifel. Look in Part VI Pile Design for information on p-y and t-z curves. This Part also covers pile installation and driveability analyses.

This book is a must-have for any engineer involved in offshore platform design and construction; and a great reference for engineers involved in pile foundation design and construction in all environments.