364
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
The water repellency and corresponding hydraulic and
geomechnical aspects needs to be adopted in engineering
practice to correctly estimate the overall behaviors. In this study,
wettable and non-wettable specimens were artificially
synthesized to preliminarily evaluate their basic properties. The
following observations can be made:
1. The critical hydraulic pressure above which water
begins permeating follows the Young’s formula. The
non-wettable sand exhibits the distinct water repellency
and the critical pressure increases with decreasing pore
size.
2. The hydraulic conductivity values of both hydrophilic
and hydrophobic sands appear alike at fully saturated
condition. Although the hydraulic conductivity with
varying degree of saturation requires further study, the
surface wettability may not affect the overall fluid flow
behavior at macro-scale.
3. From a series of the direct shear tests using the
hydrophilic and hydrophobic sands, the surface
modification at sub-micrometer scale clearly reduce the
shear strength of hydrophobic sand at dry condition.
The effect of degree of saturation is minimized for
hydrophobic sand due to the less defined meniscus at
inter-particle contacts. Yet, the shear strength of
hydrophilic sand evolves with varying degree of
saturation, exhibiting the maximum value at ~ 50%.
5 ACKNOWLEDGEMENTS
This research is supported by the basic science research
program (No. 2012-0008233) and the Public welfare & Safety
research program (No. 2012M3A2A1050975) through the
National Research Foundation of Korea(NRF) funded by the
Ministry of Education, Science and Technology.
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