Ice Lens Growth Research Articles

Artificial Ground Freezing—On the Soil Deformations during Freeze–Thaw Cycles

Artificial ground freezing (AGF) has emerged as a prominent treatment method due to its ability to mechanically strengthen the soil while reducing its permeability. However, its implementation has raised concerns about its impact, particularly with respect to frost heave and subsequent thaw-induced displacements. These soil movements can cause subsidence and pose a significant threat to the integrity of surface structures. Overburden pressure plays a crucial role in AGF and determines the amount of heave generated. This paper presents an analysis of the existing literature about soil freezing and thawing. The aim is to offer an understanding of these processes, specifically with regard to their application in AGF. This paper explains the behavior of soil during freezing, with particular emphasis on the influence of overburden pressure. It also investigates frozen soils’ thawing and freeze–thaw (FT) cycles’ long-term effects on soil properties. AGF offers improved soil strength and reduced water permeability, enhancing construction project stability. However, the interplay between the temperature, soil composition, and initial ground conditions during freezing is complex. This thermo-hydro-chemo-mechanical process strengthens the soil and reduces its permeability, but it can also induce frost heave due to water expansion and ice lens formation. Overburden pressure from the overlying soil limits ice lens growth. FT cycles significantly impact soil properties. In fine-grained soils, FT cycles can lead to over-consolidation, while rapid thawing can generate high pore pressures and compromise stability. Importantly, FT acts as a weathering mechanism, influencing soil properties at both the microscopic and macroscopic scales. These cycles can loosen over-consolidated soil, densify normally consolidated soil, and increase overall hydraulic conductivity due to structural changes. They can also weaken the soil’s structure and deteriorate its mechanical performance.

Psychrophiles to control ice-water phase changes in frost-susceptible soils

The phase changes of soil water or porous media have a crucial influence on the performance of natural and man-made infrastructures in cold regions. While various methods have been explored to address the impacts of frost-action arising from these phase changes, conventional approaches often rely on chemicals, mechanical techniques, and the reuse of waste materials, which often exhibit certain limitations and environmental concerns. In contrast, certain organisms produce ice-binding proteins (IBPs) or antifreeze proteins (AFPs) to adapt to low temperatures, which can inhibit ice crystal growth by lowering the freezing point and preventing ice crystallization without the need for external intervention. This study explores the potential of three psychrophilic microbes: Sporosarcina psychrophile, Sporosarcina globispora, and Polaromonas hydrogenivorans, to induce non-equilibrium freezing point depression and thermal hysteresis in order to control ice lens growth in frost-susceptible soils. We hypothesize that the AFPs produced by psychrophiles will alter the phase changes of porous media in frost-susceptible soils. The growth profiles of the microbes, the concentration of released proteins in the extracellular solution, and the thermal properties of the protein-mixed soils are monitored at an interval of three days. The controlled soil showed a freezing point of − 4.59 °C and thermal hysteresis of 4.62 °C, whereas protein-treated soil showed a maximum freezing point depression of − 8.54 °C and thermal hysteresis of 7.71 °C. Interestingly, except for the controlled sample, all the protein-treated soil samples were thawed at a negative temperature (minimum recorded at − 0.85 °C). Further analysis showed that the treated soils compared to porous media mixed soil freeze (1.25 °C vs. 0.51 °C) and thaw (2.75 °C vs. 1.72 °C) at extensive temperature gap. This freezing and thawing temperature gap is the temperature difference between the beginning of ice core formation and completed frozen, and the beginning of ice core thawing and completed thawed for the treated soil samples selected from different incubation days. Overall, this study presents a novel bio-mediated approach using psychrophilic microbes to control ice formation in frost-susceptible soils.

Effect of Anionic Polyacrylamide Polymer on Frost Heave Mitigation and Its Implication for Frost-Susceptible Soil.

Seasonally frozen ground regions occupy approximately 55% of the exposed land surface in the Northern Hemisphere, and frost heave is the common global problem in seasonally frozen soil areas. Frost heave induces uneven deformation of ground and damages railways, road paving, and buildings. How to mitigate frost heave is the most important technical issue in this field that has provoked great interest. Here, using freezing experiments, we investigate the effect of anionic polyacrylamide (APAM) polymer on frost susceptible soil. The results demonstrate a so-far undocumented inhibition of frost heave by APAM in freezing soil, namely APAM (tested at concentrations from 0.0 wt% to 0.60 wt%) slows down the frost heave by a factor of up to 2.1 (since 0.60 wt% APAM can decrease frost heave from 8.56 mm to 4.14 mm in comparison to the control experiment). Moreover, it can be observed that the maximum water content near the frozen fringe decreased from 53.4% to 31.4% as the APAM content increased from 0.0 wt% to 0.60 wt%, implying a mitigated ice lens growth. Hydrogen bonding between APAM and soil particles triggers an adsorption mechanism that accumulates soil particles, and thus can potentially inhibit the separation and growth of the ice lens. Moreover, the residue of APAM due to hydrogen bonding-induced adsorption in the pores of granular media may narrow seepage channels (capillary barriers) and provide an unfavourable condition for water migration. The use of APAM can also increase the viscosity of the solution, which causes a greater water migration resistance. This research provides new insights into APAM-influenced frost heave (introducing APAM into the soil can induce bridging adsorption between APAM polymer segments and a particle surface), can enable engineers and researchers to utilise chemical improvement design and to consider suitable actions (e.g., by injecting APAM solution into a frost susceptible soil or using APAM-modified soil to replace the frost susceptible soil) to prevent frost heave from having a negative impact on traffic roads and buildings in cold regions.

Influence of freezing directionality on the permeability of silty clay

During artificial ground freezing, freezing may undergo in directions either parallel or normal to the flow of water, which may result in different permeability for the water to flow. Therefore, it is of significant importance to observe the influence of freezing directionality on the permeability of soils. A set of laboratory permeation tests were performed in this study on specimens subjected to three freeze-thaw modes. Considerable change in hydraulic conductivity subsequent to freeze-thaw event was found even under condition where volume change was not allowed. Vertical freeze-thaw resulted in the lowest level of hydraulic conductivity as compared with the other two cases, irrespective of dry density and moisture content. The permeability of specimen subsequent to radial freezing was approximately 34 times in maximum greater than that subsequent to vertical freezing. The occurrence of vertical cracks was responsible for the dramatical increase in hydraulic conductivity of specimens after radial freeze-thaw. Vertical freeze-thaw, however, resulted in an apparent reduction in hydraulic conductivity because of the local consolidation of soil structure during the growth of horizontal ice lenses. Processes that larger pores became larger but smaller pores became smaller contributed to the increase in hydraulic conductivity of thawed specimens even though the total void ratio was unchanged.

Growth Mechanism of Ice Lens in Saturated Clay Considering Surface Charge

The main purpose of this study is to reveal the growth mechanism of ice lens in saturated clay. The deformation and fracturing of clay skeletons caused by ice crystal growth during the freezing process are gradually discussed, and a theoretical model for the whole process of ice lens growth considering the surface charge is proposed. Firstly, the electrical properties of clay surfaces and the pore structure characteristics of frozen clay are introduced, and the stress of pore walls during the growth of single pore ice crystals is calculated. Secondly, the values of parameters in the theoretical formula of separation pressure between adjacent clay particles are given when considering the linear elasticity of clay. Finally, the formation mechanism of the new lens is described, and the crack growth velocity equation is given. This paper shows that: there is a good consistency between the soil tensile strength of the macroscopic dimension and the intergranular separation pressure of the molecular dimension in judging the production conditions of the new lens; the formation of the new ice lens is the result of the destruction of the pore structure and the propagation of cracks caused by the growth of ice crystals, and more pore freezing can be caused only when the infiltration path of the ice crystals is formed in the pore structure. In order to verify the model, the ultimate compressive strength of soil calculated in this study was compared with the existing test results, and the rationality and correctness of the model are discussed. This study is of great significance to accurately understand the frost heave process.

Formation and growth of multiple, distinct ice lenses in frost heave

AbstractThis paper presents a fully coupled thermo‐hydro‐mechanical (THM) model which simulates frost heave in fully saturated soils. The model is able to simulate the formation and growth of multiple distinct ice lenses. The basic equations of the system were derived using the continuum theory of mixtures, nonequilibrium thermodynamics, and fracture mechanics, considering skeleton deformation, water flow and heat transport. Central to this model is the coupled transport of mass due to the temperature gradient across the frozen fringe, which acts as the main driving force of the phenomenon. The model is formulated in terms of measurable physical properties and thus no ad hoc parametrization is required. In an ice‐lens‐free state, the system is solved as a continuum using the finite element method (FEM). It is then locally treated as a discontinuous system upon the formation of ice lens, by enriching the elements carrying the embedded ice lens(es) using the extended finite element method (X‐FEM). The accuracy and efficiency of the proposed model has been verified using several laboratory tests on Devon silt samples at different overburden pressures and thermal boundary conditions. Shut‐off pressures have been also estimated and compared with the experimental results.

Experimental Study on Frost Heave Behavior of Steel Fiber Improved Soil

The incorporation of steel fibers into the natural soil is generally considered to be a novel and effective way to reduce the amount of frost heave induced by an artificial freezing process in underground engineering. In order to analyze the frost heave behavior of the steel fiber improved soil, a one-dimensional frost heave test under the open recharge system was conducted in this paper, focusing on the influence of steel fiber content, size, and soil properties. The results show that small amounts of steel fibers in the soil will not significantly affect the freezing process and temperature distribution, while the water-conducting properties of the steel fibers and the effect of limiting the ice lens growth can reduce the frost heave rate of the samples incorporated with 0.5% steel fibers by 26.93%. At the same time, the reduction effect of the frost heave rate increases linearly with the increase of steel fiber content and length but weakens with the increase of steel fiber diameter. In terms of soil property influence, the frost heave rate of the clay samples was reduced by 14.31% compared to the silt samples, while the water migration was reduced by 11.99%. In addition, the cementation of the steel fibers with the soil will also inhibit the growth of the ice lens and reduce the external water migration, thus significantly lowering the frost heave rate. The results can provide a reference for the research of the frost deformation of similar modified soils.

Theoretical Study on Freezing Separation Pressure of Clay Particles with Surface Charge Action

This study aimed to clarify the mechanism of the effect of surface charge of clay particles on the separation pressure between adjacent frozen clay particles. A general mathematical model of separation pressure between adjacent spherical clay particles was given based on the extended colloidal stability (DLVO) theory; it was introduced into the frost heave process, and the functional expression of separation pressure and freezing temperature between clay particles was derived by using the relationship between the pore throat’s radius and freezing temperature, which was verified by the existing experimental results. Finally, the effects of the freezing temperature, mineral species and solution concentration on the freezing separation pressure and ice-lens growth were analyzed. Our results show that the surface distance of adjacent charged bodies is a single-valued function of their separation pressure, but the freezing temperature is the main factor affecting the separation pressure between adjacent frozen clay particles; the separation pressure between adjacent clay particles is proportional to its surface-charge density. For the same particle spacing, the separation pressures of kaolinite and illite are not much different, but they are both about one order of magnitude lower than montmorillonite; the separation pressure between clay particles is negatively correlated with the solution concentration. When the solution concentration is less than 0.1 mol·m−3, the effect of the solution concentration on the separation pressure between particles is negligible. The research results can provide a theoretical reference for improving the existing geotechnical frost heave theory.

Multi‐phase‐field microporomechanics model for simulating ice‐lens growth in frozen soil

AbstractThis article presents a multi‐phase‐field poromechanics model that simulates the growth and thaw of ice lenses and the resultant frozen heave and thaw settlement in multi‐constituent frozen soils. The growth of segregated ice inside the freezing‐induced fracture is implicitly represented by the evolution of two‐phase fields that indicate the locations of segregated ice and the damaged zone, respectively. The evolution of two‐phase fields is induced by their own driving forces that capture the physical mechanisms of ice and crack growths, respectively, while the phase‐field governing equations are coupled with the balance laws such that the coupling among heat transfer, solid deformation, fluid diffusion, crack growth, and phase transition can be replicated numerically. Unlike phenomenological approaches that indirectly capture the freezing influence on the shear strength, the multiphase‐field model introduces an immersed approach where both the homogeneous freezing and the ice‐lens growth are distinctively captured by the freezing characteristic function and the driving force accordingly. Verification and validation examples are provided to demonstrate the capacities of the proposed models.

Thermal-Hydraulic-Mechanical Coupling Research on Overburden Pressure Mitigated Ice Lens Growth in the Freezing Soil

Frost heave induced ground surface uplift can have a destructive impact on infrastructures when freezing methods are used for underground construction. The complexity of overburden pressure and the coupled heat and mass transport interaction and their relation to different water flow rates make frost heave modelling an interesting but challenging task. A frost heave model describing phase transition and multiphase interactions (liquid-crystal-soil matrix) is presented in this paper and used to investigate the kinetic growth of the ice lens. By introducing water activity determined growth rate of ice crystals, the micro- and mesophysical mechanisms underlying ice lens growth involve ice crystal nucleation, crystallization, phase transition, and water migration in the frozen fringe are explored. This work indicates that the frozen fringe thickness, the ice crystals growth and the cryogenic-suction in the frozen fringe are particularly significant in determining the ice lens growth kinetics (frost heave) under different overburden pressures. The variation in ice lens growth under various overburden pressures appears to be controlled by the water flow path, cryogenic-suction, and permeability of the frozen fringe. This research reveals the kinetic growth of the ice lens, and helps to evaluate and mitigate geological hazards when artificial ground freezing is applied.

Numerical modelling of distinct ice lenses in frost heave

Frost heave happens when three conditions coincide: the temperature is below the normal freezing point of bulk water, the sub-cooled water is connected to a water reservoir, and the mechanical conditions of the soil allows the ice lens to grow. Upon further penetration of the freezing front, the relative permeability of the soil around the growing ice lens may dramatically decrease, and the ice lens stops growing. Then, if the three requirements for initiating a new ice lens coincide again, another ice lens will appear and start to grow. In this paper, a new thermo-hydro-mechanical (THM) model has been developed to capture the formation and growth of multiple ice lenses in a freezing ground. Non-equilibrium thermodynamic theory was used to derive the coupled transport equations of heat and mass. Fracture mechanics has been employed to handle the mechanical requirements for the position and growth of ice lens. The governing partial differential equations have been solved using the extended finite element method (X-FEM). In this method, the ice lens is treated as a kind of discontinuity inside the corresponding elements.

Transport coefficients and pressure conditions for growth of ice lens in frozen soil

In this paper, the transport of sub-cooled water across a partially frozen soil matrix (frozen fringe) caused by a temperature difference over the fringe, is described using non-equilibrium thermodynamics. A set of coupled transport equations of heat and mass is presented; implying that, in the frozen fringe, both driving forces of pressure and temperature gradients simultaneously contribute to transport of water and heat. The temperature-gradient-induced water flow is the main source of frost heave phenomenon that feeds the growing ice lens. It is shown that three measurable transport coefficients are adequate to model the process; permeability (also called hydraulic conductivity), thermal conductivity and a cross coupling coefficient that may be named thermodynamic frost heave coefficient. Thus, no ad hoc parameterizations are required. The definition and experimental determination of the transport coefficients are extensively discussed in the paper. The maximum pressure that is needed to stop the growth of an ice lens, called the maximum frost heave pressure, is predicted by the proposed model. Numerical results for corresponding temperature and pressure profiles are computed using available data sets from the literature. Frost heave rates are also computed and compared with the experimental results, and reasonable agreement is achieved.

Breaking it Down: Mechanical Processes in the Weathering Engine

The vast diversity of landscapes found on Earth results from interplay between processes that break rock down, produce mobile regolith, and transport materials away. Mechanical weathering is fundamental to shaping landscapes, yet it is perhaps less understood at a mechanistic level than chemical weathering. Ubiquitous microfractures in rock propagate and grow through a slow process known as subcritical cracking that operates at the low applied stresses common in the near-surface. Subcritical cracking is the most likely explanation for the mechanical processes associated with thermal stress, ice lens growth, mineral alteration, and root growth. The long timescales over which critical zone architectures develop require an understanding of slow processes, such as subcritical cracking.

Frost heave in freezing soils: A quasi-static model for ice lens growth

Frost heave can have a very destructive impact on infrastructure in permafrost regions. The complexity of nanoscale ice-mineral interactions and their relation to the macroscale frost heave phenomenon make ice lens growth modeling an interesting but challenging task. Taking into account the limiting assumption of the constant segregation temperature in the segregation potential model, we propose here a new quasi-static model for ice lens growth under a time varying temperature based on the water activity criterion. In this model, the conventional pressure potential gradient in Darcy's law is replaced by a water activity based chemical potential gradient for the calculation of water flow velocity, which provides a better prediction of ice lens growth and is useful to describe the ice nucleation and the state of water at a specific temperature. Moreover, based on the analysis of the new developed model, a mathematical description of the segregation potential is provided here. The modified Kozeny-Carman equation is applied to determine the water permeability of a given soil. In our new model, the effects of the equivalent water pressure are taken into account to modify the freezing characteristic function. Hence, the temperature- and equivalent water pressure- dependent hydraulic permeability in the frozen fringe is mathematically determined and improved. By coupling the quasi-static model with the modified hydraulic permeability function, the numerical calculation of ice lens growth is validated based on the experimental data of the temperature of the ice lens measured in the laboratory. The prediction of ice lens growth using the proposed method contributes and facilitates the simplified calculation of frost heave in the field and/or laboratory scenarios at a quasi-static state, and thus enables a better understanding of phase change and fluid flow in partially frozen granular media (soils).

A separate-ice based solution for frost heaving-induced pressure during coupled thermal-hydro-mechanical processes in freezing soils

A frost heaving-induced pressure (FHIP) solution is developed in this paper based on the proposed separate-ice frost heave model. A coupled thermal-hydro-mechanical (THM) model, describing the growth of a single ice lens under the restraint, is firstly constructed by considering the relationship between soil porosity and effective stress. The new ice lens formation criterion indicates that the formation of a new ice lens occurs when the disjoining pressure at the ice-water interface exceeds the summation of the external pressure and the critical pressure of soil strength. With consideration of the influence of the external pressure on the deformation of unfrozen soil, equivalent water pressure and critical separation pressure for ice segregation, the FHIP model is established by combining the growth model of a single ice lens and the formation criterion of new ice lenses. The freezing tests of Xuzhou (China) silty clay under different restraints were conducted to verify our numerical results, and the observed consistency thus validates the FHIP model. Our numerical results demonstrate the stress induced deformation of the soil column and indicate that the FHIP increases with the restrained stiffness. Particularly, with the decrease of the restrained stiffness, the FHIP decreases following an exponential function. The prediction of the FHIP using the proposed method improves our understanding of the characterized behavior of the FHIP under various restraints, and thus contributes to the analysis of the coupled thermal-hydro-mechanical processes in freezing soils.

Separate-ice frost heave model for one-dimensional soil freezing process

For one-dimensional soil freezing process, a separate-ice frost heave model is established, and the coupled process of heat transfer, fluid flow and stress development is considered in the model. First, a coupled heat–fluid–stress model describing the growth of a single ice lens is developed by extending the coupled heat–fluid model presented by Zhou and Zhou (Can Geotech J 49(6):686–693, 2012). Second, the mechanism for the formation of a new ice lens in the frozen fringe is studied, and we indicate that if the total vertical disjoining pressure at certain place exceeds the sum of the external pressure and the critical pressure, a new ice lens will emerge. By combining the growth model of a single ice lens and the criterion for the formation of a new ice lens, the separate-ice frost heave model is then established. The difference between the separate-ice model and the rigid-ice model is explained, and the relations for different mathematical models which describe the soil freezing process are also discussed. Numerical analysis of the separate-ice model is conducted using the finite volume method. The freezing tests for Devon silt under no external pressure and Xuzhou silty clay under a constant external pressure are applied to verify the computational results. The consistence between the calculation and the observation validates the separate-ice frost heave model.

Multi-scale numerical simulation analysis for influence of combined leaching and frost deteriorations on mechanical properties of concrete

Purpose The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate the long-term behavior of concrete in service and bridges the gap between research on the material and on the structural level. However, the combined chemical-physical deterioration mechanisms of concrete remain a challenging task. The purpose of this paper is to investigate the degradation mechanism of concrete at the waterline in cold regions induced by combined calcium leaching and frost damage. Design/methodology/approach With the help of the NIST’s three-dimensional (3D) hydration model and the random aggregate model, realistic 3D representative volume elements (RVEs) of concrete at the micro-, the meso-, and the macro-scales can be reconstructed. The boundary problem method is introduced to compute the homogenized mechanical properties for both sound and damaged RVEs. According to the damage characteristics, the staggering method including a random dissolution model and a thermo-mechanical coupling model is developed to simulate the synergy deterioration effects of interacted calcium leaching and frost attacks. The coupled damage procedure for the frost damage process is based on the hydraulic pressure theory and the ice lens growth theory considering the relationship between the frozen temperature and the radius of the capillary pore. Finally, regarding calcium leaching as the leading role in actual engineering, the numerical methodology for combined leaching and frost damage on concrete property is proposed using a successive multi-scale method. Findings On the basis of available experimental data, this methodology is employed to explore the deterioration process. The results agree with the experimental ones to some extent, chemical leaching leads to the nucleation of some micro-cracks (i.e. damage), and consequently, to the decrease of the frost resistance. Originality/value It is demonstrated that the multi-scale numerical methodology can capture potential aging and deterioration evolution processes, and can give an insight into the macroscopic property degradation of concrete under long-term aggressive conditions.

Experimental and theoretical investigations into the formation of ice lenses in deformable porous media

The aim of this paper is to increase the understanding of ice lens initiation and growth in freezing soil. A model describing the growth process of ice lenses in soils has been established. The model presented here, which considers a series of processes, including heat transfer, water migration, phase change, ice lens formation, soil deformation, is solved by the use of a transient finite element. The simulated results agree with the experimental data. Results show that: (1) Negative pore water pressure occurs in unfrozen areas, this result in the water transfers from the unfrozen zone to the frozen zone and substantial water was stored in the frozen zone which results in oscillation with in water content distributions. (2) Few segregation ice lenses appeared in the fast freezing section, several thin and discontinuous segregation ice lenses appeared in the transitional section, and thick ice lenses appeared in the third phase when the freezing front tended to be stable. (3) Both the consolidation process and the expansion process are in progress during the freezing process, due to the migration of unfrozen water. (4) The frost heave model is composed of two aspects: the coupled heat-mass transport and the growth of ice lens. Numerical modeling is able to represent the development of both the thermal field and ice segregation observed in the physical models.

Macroscopic ice lens growth in hardened concrete

Spalling of concrete has been observed in water retaining concrete structures exposed to long periods of freezing weather. A hypothesis is that poor quality concrete, inadequate compaction or aging make hardened concrete susceptible to macroscopic ice lens growth, i.e. ice segregation. To simulate winter conditions, the top surface of concrete specimens was subjected to freezing, whereas the bottom surface was submerged in heated water. Given constant thermal conditions, ice segregation occurred in sound concrete with w/c-ratio 0.9 and higher. In concrete with internal frost damage, ice segregation occurred within a few days regardless of the w/c-ratio. Ice segregation also occurred in specimens with paper sheets cast into the concrete to form cavities. However, the period of freezing required to facilitate ice segregation increased with decreasing w/c-ratio. The risk of macroscopic ice lens growth in actual structures cannot be overlooked since unfavourable temperature and moisture conditions may exist in winter.

The origin of relic cryogenic mounds at East Walton and Thompson Common, Norfolk, England

Contemporary pingo and lithalsa mounds are features which develop exclusively within cold climate environments in areas of continuous and discontinuous permafrost. The presence of pingo and lithalsa remnants as rampart enclosed ponds has been documented across temperate areas of the Northern Hemisphere and has been used to establish the extent of former permafrost. Two sites thought to be remnants of hydraulic pingo forms were investigated at East Walton and Thompson Common(s) in order to establish a precise origin. Through Ground Penetrating Radar and Electrical Resistivity Tomography the structure of ramparts and hollows has been investigated and interpreted. Linking this with physical and ground invasive techniques and a consideration of the hydrogeological setting it was apparent that the two sites had different origins. The topography, geology and hydrogeology of the East Walton area are a stereotypical setting for the development of hydraulic pingos. In contrast, the development of features within the Lowestoft Till and weathered Chalk Formations at Thompson Common implies that forms resulted from the heave of material through segregation ice lens growth. This has led to the creation of a model at East Walton which documents the development of remnant pingo ramparts and the strata which result. It is proposed that this model can be used in the study of similar landforms.