Hardening Soil Parameters (PLAXIS2D)

[josephbutarbutar]

Hello guys, so this is my first time posting, so sorry if I break any rules here.

So right now I'm modelling a reclamation project as a final project of my bachelor degree, using hydraulic fill. And I'm planning using soft soil as top original soil model (NC Clay) and the rest I'm planning to use hardening soil. But the problem is, I lack of triaxial data to determine the E50ref. Eoedref, and Eurref.

So what I'm gonna ask is, is there any correlation get these parameters : 50ref. Eoedref, and Eurref? By using N-SPT or by using any other data, like consolidation data?

The condition is I got complete enough consolidation data, N-SPT data.

I really need help to this project.

 

[bdbd]

There are several:

Eu/N60 = (1-1.2) MPa by Butler (1975).
Jardine has this chart which I like. You can use that to correlate cu to Eu. (Jardine, 1985)

Other parameters: Plaxis Reference Manual says that: E50=Eoed while Eur is the 3 times of the E50.
What do they influence? Eur is about the heave. When you excavate, soil will heave. If you increase Eur, heave will be less. I have seen papers that says 7 x E50 = Eur is not uncommon.


So, I would use 400cu = E50 = Eoed.Eur = 1200 cu. But OF COURSE THERE ARE OTHER CONSIDERATIONS like Eoed = 1/mv etc. But, you are doing your project. Go on before oldestguy arrives.

 

[LRJ]

E_oed comes from oedometer data or other 1D consolidation data. But I think bdbd has covered it all really.

I would suggest doing some sensitivity analyses if you are unsure of anything. It would also be good for your dissertation as it shows your tutors that you have considered the effects of changes in/variation of the input parameters.

 

[bdbd]

LRJ,

What do you prefer? I usually calibrate the model if I want to see real consolidation settlements. But, I have never achieved this by using Eoed=1/mv.