This study introduces numerical frameworks for simulating the interactions within soil
systems subjected to freezing and thawing processes, crucial for addressing geotechnical
challenges in cold regions. By integrating robust thermo-hydro-mechanical (THM), this
research offers a general understanding and specific insights into the deformation, thermal,
and moisture transport behaviors of freezing-thawing soils.
The first part of this study presents a soil freezing characteristic curve (SFCC) adaptable
to various computational frameworks, including THM models. The SFCC, enhanced
by an automatic regression scheme and a smoothing algorithm, accommodates the dynamic
changes in soil properties due to phase transitions. This model effectively captures
the unique behaviors of different soil types under freezing conditions, addressing key
factors such as freezing temperature, compaction, and mechanical loading.
Building on this foundation, the second framework employs the phase-field method
(PFM) coupled with THM to model the behavior of ice-rich saturated porous media.
This approach advances the field by enabling distinct representations of the mechanical
behaviors of ice and soil through a diffused interface, introducing anisotropic responses
as the soil undergoes freezing. By integrating a transversely isotropic plastic constitutive
model for ice, this method provides a tool for capturing the phase transition processes
and the resulting mechanical responses of frozen soil.
The third part extends these methodologies to model thaw consolidation in permafrost
regions using a THM framework combined with phase field methods. This model incorporates
internal energy functions and a multiscale modified Cam-Clay model within
a damage phase field framework, adept at capturing the simultaneous effects of phase
change and particle rearrangement. Through validation against experimental scenarios,
this model demonstrates its effectiveness in understanding the microstructural evolution
and plastic softening in thaw-sensitive soils, which is vital for enhancing infrastructure
resilience under thaw conditions.
Together, these integrated approaches represent a leap in the modeling and simulation
of geotechnical behaviors in cold regions, offering potential applications in predicting and
mitigating the impacts of climate change on permafrost and other freeze-thaw affected
terrains. / Thesis / Doctor of Science (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/30247 |
| Date | January 2024 |
| Creators | Malekzade Kebria, Mahyar |
| Contributors | Tighe, Susan, SeonHong Na, Civil Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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