DYNAMICS OF UNFROZEN WATER IN FROZEN SOIL

Masaru Mizoguchi
Department of Bioresources, Mie University
Email: mizo@bio.mie-u.ac.jp


1. What is Unfrozen water?

Liquid water exits in frozen materials(soil, etc.) while bulk water freezes at 0

2. Unfrozen water characteristics

20-30 water molecules in thick at -1
Dissolved salt increases unfrozen water

(Fig. Unfrozen water content measured by Ishizaki ,1994)

3. Why is unfrozen water important?

Frost action:
damages highway, plant roots, etc.
cause soil erosion
is used as artificial ground freezing tech.
Need to clarify mechanism of frost heaving

Soil contamination is threatening us as:
Industrial wastes problem
Contaminated ground water, LUST (Leaking Underground Storage Tank)
Need more information on: Soil-chemicals interaction
Adsorption of heavy metals on soil component,
Finger flow in soil
Thin film water on surface relates to many phenomena in soil.

4. Mechanism of frost heaving

Unfrozen film water moves to ice lens due to chemical potential gradient of soil water.
(Ice segregation pictured by Watanabe, 1996)

5. Clean-up technique of contaminated soil

Freezing Electro-Osmosis technique by mizo(1996)
Need more information on movement of concentrated unfrozen water by electro-osmosis

6. Model to predict unfrozen water movement in soil

SHAWS(Simultaneous Heat And Water & Salt) model by mizo(1990)
"Blind" parameters:
Chemical potential of unfrozen water
Viscosity of unfrozen water
Need information on properties of unfrozen water

7. Nano-scale soil-water interaction

Developed computer chemistry
Challenge to MD method for Argon fluid
Force between two micas in KCl solution
(Fig.after Israelachvili, 1983)
Unfrozen water may be within a range of hydration force!
Fig. after Ishizaki (1994)

8. Questions about unfrozen water

Why does it exit?
Electric double layer force
van der Waals force
Hydration (solvation/structural) force
How does it exit?-static
Quantity/Structure
How does it move?-dynamic
Viscosity

9. Hope to measurement technique for unfrozen water

Need a new technique to measure nano-scale (hydration) force
Look forward to learning a fundamental topic in this symposium

References

T.Ishizaki, et. al, Proc. 7th Int. Symp. on Ground Freezing, 85(1994)
Y.Furukawa , et. al, J. Crystal Growth, 189(1987)
M.Mizoguchi, Dr. thesis in Tokyo Univ.(1990)
M.Mizoguchi, http://buturiPc6.bio.mie-u.ac.jp/openpro/shaws.html(1996)
M.Mizoguchi , et. al, Proc. JSIDRE, 274(1996)
K.Watanabe , et. al, Proc. JSIDRE, 250(1996)