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Summary The mechanical and hydraulic properties of unsaturated clay under nonisothermal conditions have practical implications in geotechnical engineering applications such as geothermal energy harvest, landfill cover design, and nuclear waste disposal facilities. The water menisci among clay particles impact the mechanical and hydraulic properties of unsaturated clay. Molecular dynamics (MD) modeling has been proven to be an effective method in investigating clay structures and their hydromechanical behavior at the atomic scale. In this study, we examine the impact of temperature increase on the capillary force and capillary pressure of the partially saturated clay‐water system through high‐performance computing. The water meniscus formed between two parallel clay particles is studied via a full‐scale MD modeling at different elevated temperatures. The numerical results have shown that the temperature increase impacts the capillary force, capillary pressure, and contact angle at the atomic scale. The capillary force on the clay particle obtained from MD simulations is also compared with the results from the macroscopic theory. The full‐scale MD simulation of the partially saturated clay‐water system can not only provide a fundamental understanding of the impact of temperature on the interface physics of such system at the atomic scale, but also has practical implication in formulating physics‐based multiscale models for unsaturated soils by providing interface physical properties of such materials directly through high‐performance computing.
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Nanoscale soil-water retention curve of unsaturated clay via molecular dynamics
This paper characterizes nanoscale soil-water retention mechanism of unsaturated clay through molecular dynamics simulation. Series of molecular dynamics simulations of clay at low degrees of saturation were conducted. Soil water was represented by a point cloud through the centre-of-massmethod. Water-air interface area was measured numerically by the alpha shape method. Spatial variation of water number density is characterized and used to determine the adsorbed water layer. The soil-water retention mechanism at the nanoscale was analysed by distinguishing adsorptive pressure and capillary pressure at different mass water contents and considering apparent interface area (water-air interface area per unit water volume).
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- PAR ID:
- 10409359
- Editor(s):
- Bardanis, M.
- Date Published:
- Journal Name:
- E3S Web of Conferences
- Volume:
- 382
- ISSN:
- 2267-1242
- Page Range / eLocation ID:
- 10007
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1051/e3sconf/202338210007
