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

2022 ◽  
Author(s):  
Yukun Ji ◽  
Guoqing Zhou ◽  
Matthew R. Hall ◽  
Veerle Vandeginste ◽  
Xiaodong Zhao
Keyword(s):  
Overburden Pressure ◽  
Mechanical Coupling ◽  
Freezing Soil ◽  
Lens Growth

Water flow induced by soil freezing

1977 ◽  
Vol 14 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Wayne D. Arvidson ◽  
Norbert R. Morgenstern
Keyword(s):  
Freezing Temperature ◽  
Soil Freezing ◽  
Frost Heave ◽  
Freezing Front ◽  
Overburden Pressure ◽  
Soil Frost ◽  
Freezing Soil ◽  
Volumetric Expansion ◽  
Pressure Water

A study to observe the effects of overburden pressure and other parameters on the freezing behavior of a saturated soil was undertaken. A linear relationship between effective overburden pressure and the flow of water into or out of a freezing soil was observed. The effective pressure at which no flow occurred was termed the shutoff pressure. At pressures less than the shutoff pressure water was sucked to the freezing front resulting in segregated ice, ice lensing, and heaving. This heaving could significantly exceed the heave due to the volumetric expansion of the in situ porewater. At pressures greater than the shutoff pressure water was expelled from the freezing front thereby reducing the volume of in situ water and resulting in a relatively small amount of heave. Shutoff pressure was observed to depend on soil type, stress history, and freezing temperature. The effects of overburden pressure upon flow of water in a freezing soil and frost heave were recommended as additional criteria for assessing soil frost susceptibility.

scholarly journals Stress–Strain Model for Freezing Silty Clay under Frost Heave Based on Modified Takashi’s Equation

2020 ◽  
Vol 10 (21) ◽  
pp. 7753
Author(s):  
Lin Geng ◽  
Shengyi Cong ◽  
Jun Luo ◽  
Xianzhang Ling ◽  
Xiuli Du ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Compressive Modulus ◽  
Freezing Rate ◽  
Frost Heave ◽  
Gradient Term ◽  
Silty Clay ◽  
Stress Strain ◽  
Overburden Pressure ◽  
Freezing Soil ◽  
Strain Behavior

In analyzing frost heave, researchers often simplify the compressive modulus of freezing soil by considering it as a constant or only as a function of temperature. However, it is a critical parameter characterizing the stress–strain behavior of soil and a variable that is influenced by many other parameters. Hence, herein several one-dimensional freezing experiments are conducted on silty clay in an open system subjected to multistage freezing by considering the compressive modulus as a variable. First, freezing soil under multistage freezing is divided into several layers according to the frozen fringe theory. Then, the correlation between the freezing rate and temperature gradient within each freezing soil layer is investigated. Takashi’s equation for frost heave analysis is modified to extend its application conditions by replacing its freezing rate term with a temperature gradient term. A mechanical model for the stress–strain behavior of freezing soil under the action of frost heave is derived within the theoretical framework of nonlinear elasticity, in which a method for determining the compressive modulus of freezing soil with temperature gradient, overburden pressure, and cooling temperature variables is proposed. This study further enhances our understanding of the typical mechanical behavior of saturated freezing silty clay under frost heave action.

The Influence of Depth of Frost Penetration on the Frost Susceptibility of Soils

1967 ◽  
Vol 4 (3) ◽  
pp. 334-346 ◽  
Author(s):  
J C Osler
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
External Pressure ◽  
Water Interface ◽  
Frost Heaving ◽  
Overburden Pressure ◽  
Freezing Soil ◽  
Frost Penetration ◽  
Ice Water

Research on heaving pressures associated with the formation of ice lenses in soils indicates that the magnitude of the heaving pressure in silt soils is governed by the geometry of the ice-water interface. This geometry involves a double curvature of the ice front, into the voids and around the adjacent particles, and thus depends on both particle and pore size distribution. A theory for predicting frost heaving pressures, which takes into account the geometry of the ice-water interface, is described and it predicts greater heaving pressures for decreasing particle and pore sizes. Supporting experimental results are given.The formation of ice lenses in a freezing soil can be arrested if the frost heaving pressure is counteracted by an equal or greater external pressure, such as overburden pressure. From the theory, the frost heaving pressure for a given particle and pore size distribution can be obtained. If this pressure is equal to the pressure of the frozen overburden, a state of equilibrium will exist and ice lenses will not form. Thus, a critical particle and pore size for a given depth of frost penetration can be predicted for which a soil will be non-frost-susceptible.

scholarly journals Experimental and Theoretical Investigations on Frost Heave in Porous Media

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Feng Ming ◽  
Dong-qing Li
Keyword(s):  
Temperature Gradient ◽  
Soil Column ◽  
Frost Heave ◽  
Overburden Pressure ◽  
Cold Regions ◽  
Freezing Soil ◽  
Finite Element Software ◽  
Theoretical Investigations ◽  
Two Factors ◽  
Increasing Temperature

For the construction in cold regions, frost heave and thaw settlement are the two factors which must be taken care of. Considered that a saturated soil column was subjected to an overburden pressure to model the ice lens growing process. A typical process, which coupled water, heat, and stress that happened in a saturated freezing soil column, was simulated by the finite element software. We did the numerical simulation under the same conditions as the experiment tests and then compared the results from temperature, frost heave, frozen structure, water content, and water intake. Result shows that the simulation results match well with the experimental results, and the correctness of the mathematical model is validated. On that basis, frost heave amount under different conditions by changing the temperature boundary and loading boundary is obtained. The frost heave has an optimum temperature gradient. Under the optimum value, the frost heave amount increases with increasing temperature gradient. Above the optimum value, frost heave decreases with increasing temperature gradient. Increasing the overburden pressure, frost heave amount always decreases. These results can provide references for the constrictions in cold regions.

Extended Porosity Rate Function for Frost Heave

2014 ◽  
Author(s):  
Basel Abdalla ◽  
Chengye Fan ◽  
Colin Mckinnon ◽  
Vincent Gaffard ◽  
Annie Audibert-Hayet ◽  
...  
Keyword(s):  
Soil Surface ◽  
Rate Function ◽  
Frost Heave ◽  
The Arctic ◽  
Temperature Cycle ◽  
Freezing Process ◽  
Extended Model ◽  
Soil Response ◽  
Freezing Soil ◽  
Lens Growth

Frost heave is a common phenomenon in the Arctic, where soil expands in the direction of heat loss due to ice lens growth upon freezing. It also occurs if a refrigerated structure is buried in unfrozen frost heave-susceptible soil, and thus special considerations are required when designing chilled or LNG pipelines in the Arctic. In the past decades, many theoretical and numerical methods have been developed to predict the frost heave of freezing soil. Among them, the rigid ice model, segregation potential model, and porosity rate function model are the most popular. These frost heave models work well in predicting the soil response during a pure freezing process, but none of these methods consider a thawing and consolidation of soil, which is the opposite but integrated process when the system undergoes the annual temperature cycle. In this study, efforts are made to extend the porosity rate function to the thawing branch based on reasonable assumptions. With the extended model, a fluctuating surface temperature can be applied on top of the soil surface to simulate a continuous changing ambient temperature. The extended model is realized in ABAQUS with user defined subroutines. It is also validated with test data available in the public domain. As an application example, the extended model is utilized to simulate a chilled gas line buried in frost-susceptible soil to estimate its frost heave over a multi-year operation.

Discrete ice lens theory for frost heave in soils

1991 ◽  
Vol 28 (6) ◽  
pp. 843-859 ◽  
Author(s):  
J. F. (Derick) Nixon
Keyword(s):  
Hydraulic Conductivity ◽  
Temperature Gradient ◽  
Frozen Soil ◽  
Soil Freezing ◽  
Frost Heave ◽  
Overburden Pressure ◽  
Discrete Location ◽  
Freezing Soil ◽  
Analytical Technique ◽  
Segregation Potential

The existing segregation potential (SP) method for frost heave prediction in soils is semiempirical in nature and does not explicitly predict the relationship between heave rate, temperature gradient, and other more fundamental soil properties. The SP method assumes that the heave rate is directly related to the temperature gradient at the frost front but acknowledges that the SP parameter is dependent on pressure, suction at the frost front, cooling rate, soil type, and so forth. This paper extends and modifies an approximate analytical technique of Gilpin and accounts for the effects of distributed phase change within the freezing fringe in both the head- and mass-transfer components of the formulation. The approach requires as input a relationship between frozen hydraulic conductivity and temperature and predicts the discrete location of each ice lens within the freezing soil. The solution can be carried out quickly on a microcomputer to obtain the heave, suction at the frost front, ice lens temperature, and other results of interest with time. Furthermore, the discrete ice lens method predicts the effects of changing overburden pressure on the predicted heave rate. A method of extracting input parameters for the discrete ice lens procedure from a series of frost heave tests is proposed. The discrete ice theory has been tested and calibrated against well-documented frost heave test results in the literature, and very encouraging agreement between prediction and observation has been obtained. Key words: frost heave, discrete ice lens, segregation potential, hydraulic conductivity of frozen soil, freezing soil.

A two degrees of freedom comb capacitive-type accelerometer with low cross-axis sensitivity

2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu
Keyword(s):  
Degrees Of Freedom ◽  
Proof Mass ◽  
Vibration Modes ◽  
Electrode Structure ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Fully Differential ◽  
Mode Effects ◽  
The Finite Element Analysis ◽  
Cross Axis

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

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