Dear Azadeh Hoor:
Let me give you a brief answer to each of the questions that you asked.
Your questions are very well defined and therefore, maybe a short answer
will be sufficient.
With regard to your first question: 1.) Matric suction in a soil can
only be changed through adding water to the soil or removing water from
the soil. Osmotic suction can be changed by changing the salt content in
the soil; that is, adding or taking salts away from the soil.
On the second question, 2.) Whether the soil swells or collapses depends
upon the magnitude of the net confining stress. There is a relationship
called the Load-Collapse curve and it defines the stress conditions
under which the soils moves froman expansive soil behavior to a
collapsing behavior.
I hope that this helps to answer your questions.
I understand that you have so many extremely expansive soils in Iran. I am
sure that unsaturated soil mechanics is of significant interest to your
people.
Regards, Del Fredlund
-----Original Message-----
From: Geotechnical Engineering Email List
[mailto:[log in to unmask]]On Behalf Of Azadeh Hoor
Sent: Sunday, August 08, 2004 8:34 AM
To: [log in to unmask]
Subject: Suction in unsaturated soils
Dear members,
I have two questions about unsaturated soils and I will be really grateful
if anyone answers them.
1-How can we change the suction of a soil? Is there any other way rather
than saturating/drying?
2-Does the decrease of suction in a constant net stress result in
swelling?(or it may in some cases result in compression)
Regards,
Azadeh Hoor
Graduate Student of Geotechnical Engineering
University of Tehran
Iran
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.735 / Virus Database: 489 - Release Date: 8/6/2004
|