Reduction in Secondary Compression due to Surcharge

[kcall2]

I am trying to estimate the secondary compression index following removal of a surcharge load. Is there a reasonable way to do this knowing the existing and future states of stress and C-alpha (normally consolidated)?

 

[fattdad]

the use of a surcharge does not affect the value of C-alpha. The surcharge has the affect of "aging" the clay layer. If you consider a clay layer that will realize 5 inches of secondary compression over a 20 year period following the addition of some load and you place a greater amount of load to cause this 5 inches to occur prior to construction, then you have "prematurly" aged the soil layer by 20 years. The new forcast for secondary compression would be what you calculate from 20 years to 40 years.

Hope this makes sense. . .

f-d

¡papá gordo ain’t no madre flaca!

 

[oldestguy]

Hey fatdad, that's a neat term (aging. Wish I would have thought of it.

 

[BigH]

Aging has been around for a while - see:

http://books.google.co.id/books?id=...ge&q=clay aging consolidation bjerrum&f=false

http://www.isope.org/publications/proceedings/ISOPE/ISOPE 2004/volume2/2004-tm-10.pdf

(reference Bjerrum 1963)

But it is a great term; I must be a clay - for I am aging!