Geomechanics and Geoenergy Journal

Geomechanics and Geoenergy Journal

Comparative Analysis of Soil and Rock Behavior Under Freeze-Thaw Cycles: Applications in Structures and Petroleum Engineering in Cold Regions

Document Type : Original Article

Authors
1 Mining Engineering, Rock Mechanics field, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
2 Rock Mechanics, Faculty of Engineering and Technology, Tarbiat Modares University, Tehran, Iran,
Abstract
The study of freeze-thaw cycles is significant due to their substantial impact on the stability of structures built in cold regions. Despite the existence of numerous models for predicting soil and rock behavior, no study has yet conducted a comparative analysis of these two media under identical thermal conditions. This research aims to bridge that gap using advanced numerical models. To this end, soil was simulated using the NTNU model in Plaxis software, while rock was modeled using the distinct element method in PFC2D software, both subjected to a shared thermal cycle (ranging from +1°C to -4°C over a two-hour period). The results demonstrated that, despite the irreversible behavior observed in both media, the mechanisms governing deformation differ significantly; in soil, the dominant phenomenon is ice segregation and the formation of ice lenses, leading to abrupt heave (approximately 2% volumetric strain) at -2°C, whereas in rock, the gradual growth of micro-cracks due to pore-water freezing results in a reduction of strength. The magnitude of change is far greater in soil than in rock, and critical temperature thresholds in rock occur at lower temperatures (-3°C). These findings indicate that soil behavior models, with appropriate calibration, can predict the behavior of highly porous rocks and have direct application in stability analysis for oil-related structures in cold regions.
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