Abstract

The freezing process of saturated soil is studied under the condition of water replenishment. The process of soil freezing was simulated based on the theory of the energy and mass conservation equations and the equation of mechanical equilibrium. The accuracy of the model was verified by comparison with the experimental results of soil freezing. One-side freezing of a saturated 10-cm-high soil column in an open system with different parameters was simulated, and the effects of the initial void ratio, hydraulic conductivity, and thermal conductivity of soil particles on soil frost heave, freezing depth, and ice lenses distribution during soil freezing were explored. During the freezing process, water migrates from the warm end to the frozen fringe under the actions of the temperature gradient and pore pressure. During the initial period of freezing, the frozen front quickly moves downward, the freezing depth is about 5 cm after freezing for 30 h, and the final freezing depth remains about 6 cm. The freezing depth of the soil column is affected by soil porosity and thermal conductivity, but the final freezing depth mainly depends on the temperatures of the top and lower surfaces. The frost heave is mainly related to the amount of water migration. The relationship between the amount of frost heave and the hydraulic conductivity is positively correlated, and the thickness of the stable ice lens is greatly affected by the hydraulic conductivity. With the increase of the hydraulic conductivity and initial void ratio, the formation of ice lenses in the soil become easier. With the increase of the initial void ratio and thermal conductivity of soil particles, the frost heave of the soil column also increases. With high-thermal-conductivity soil, the formation of ice lenses become difficult.

Highlights

  • Permafrost in China is mainly distributed in high latitudes

  • The effects of the initial void ratio, hydraulic conductivity, and thermal conductivity of soil particles on temperature is below the freezing temperature, and the unfrozen water adsorbs on the surface of the soil freezing process are explored

  • According to Miller’s second theory of frost heave, there is a frozen fringe in the process of soil freezing, and a new ice lens is formed in the frozen fringe

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Summary

Introduction

Permafrost in China is mainly distributed in high latitudes. With the change of temperature, water and ice in the pores of frozen soil can transform into each other. Taber [6] studied the soil freezing process by an experimental method to explain the frost heave of soil and the formation of ice lenses. Established a hydrothermal coupling model for partially frozen soil based on the analogy of the mechanism of water transport in partially frozen soils and unsaturated soils This model cannot explain the formation of ice lenses. Tan et al [15] established a thermo-hydro coupling model and focused on the evolution of the temperature field and simulated the freezing process of the soil column without water replenishment. A new thermo-hydro-mechanical coupling model is established to describe the freezing process in soil. A of new thermo-hydro-mechanical coupling model is established to describe the

Theoretical
Theoretical Model of Soil Freezing
Heat Transfer
Mechanical Equilibrium
Water Migration
Ice Segregation
Model Validation and Numerical Analysis
Model Validation
Comparison
The Effect of Soil Parameters on the Soil Freezing Process
The linear outside outside of of the the
Temperature
10. Freezing process
Discussion
Full Text
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