...> Dear Sir/Madam:
...>
Dear Limin,
...> I have a question to ask,they are as the followings.
...>
This is an interesting question.
...> I am now using a FEM program based on Biot consolidation theory to do
...> a two dimensional calculation for my dissertation. I try to assess the
...> consolidation rate of soft clay ground improved by deep mixing method
...> which final displacements are not same as the nature ground. But I am
...> comfused by one question: How can I determine the ground improved by
...> deep mixing method consolidate faster or slower than the nature
...> ground.
By using deep mixing, the ground should be stiffer and consolidation
should be faster. But on the other hand, the permeability would be
reduced, the consolidation should be slower. On balance, the amount
of settlement should be reduced but the consolidation should take
longer.
...> Since the displacementand excess pore water pressure are
...> interactive based on Biot consolidation theory.
There is no difference with Terzaghi consolidation except the Biot
alpha factor.
...> Is the conception of
...> the "degree of consolidation"(defined by excess pore water pressure)
...> still useful? In two dimensinal consolidation analysis,can I compare
...> the rate of consolidation by average consolidation degree defined by
...> the nodal vertical displacement which is just under the loading and
...> in the middle?
...>
If you want to use "degree of consolidation", you should consider all
nodes affected. Since the distribution of excess pore water pressure
is not uniform, it would NOT have a linear relationship with the
settlement at the ground level.
...> I will appreciate you if you kindly give me some advices.
...>
I hope this is useful.
...> Best regards!
...>
...> L. Chen
...>
...>
...>
regards,
Andrew
...> ______________________________________________________
...> Get Your Private, Free Email at http://www.hotmail.com
...>
--
If a failure has to come in one's life, it'd better if it comes early.
Dr. Andrew H.C. Chan: [log in to unmask] or [log in to unmask]
Reader, School of Civil Engrg, Univ of Birmingham B15 2TT UK
Tel: +44(0)121 414 5100 Fax: +44(0)121 414 3675 Room 118B
http://www.bham.ac.uk/CivEng/pg/soils/chan/chan01.htm
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