Saturation times

[OCclay101]

Hi,

I am trying to estimate the saturation time of very stiff over-consolidated 100mm triaxial samples. I have heard that 38mm triaxial samples can take 2-4 weeks. Any thoughts?

Thanks.

 

[fattdad]

are you using backpressure? If you maintain 5psi of effective stress (sigma 3 minus backpressure), you can increase the cell and backpressure simultaneously and get the air in the voids to go into solution. The b-value is used to evaluate the extent of saturation.

f-d

ípapß gordo ainÆt no madre flaca!

 

[OCclay101]

Yes I was going to saturate by maintaining a small effective stress and increasing the cell pressure and back pressure and using the B-value to check. I am broadly using the BS1377 methodology. No-one here has done this before so really don't know how long it will take. Samples have permeability between 1e-9 - 1e-11. I have read a thesis by Gasparre 2005 who deals with similar material but no time is specified.

 

[fattdad]

what units do you use for permeability?

f-d

ípapß gordo ainÆt no madre flaca!

 

[OCclay101]

I am using m/s. sorry.