Feasibility study on ice content measurement of frozen soil using actively heated FBG sensors

Abstract Proper simulation of soil freezing and thawing processes is an important issue in cold region climate studies. This paper reports on a frozen soil parameterization scheme for cold region studies that includes water flow and heat transfer in soil with water phase change. The mixed-form Richards’ equation is adopted to describe soil water flow affected by thermal processes in frozen soil. In addition, both liquid water and ice content have been taken into account in the frozen soil hydrologic and thermal property parameterization. To solve the complex nonlinear equation set and to ensure water conservation during simulation of complex phase change processes, efficient computational procedures have been designed and a new modified Picard iteration scheme is extended to solve the mixed-form Richards’ equation with phase change. The frozen soil model was evaluated using observational data from the field station at Rosemount, Minnesota, and the Tibet D66 site. The results show that the model is capable of providing good simulations of the evolution of temperature and liquid water content in frozen soil. Comparisons of simulation results from sensitivity studies indicate that there is a maximum difference of about 50 W m−2 in sensible and ground heat fluxes with and without the inclusion of the effect of ice content on matric potential and that using the exponential relationship between hydraulic conductivity and ice content produces realistic results.

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In situ measurements of moisture and salt movement in freezing soils

Canadian Journal of Earth Sciences ◽

10.1139/e86-069 ◽

1986 ◽

Vol 23 (5) ◽

pp. 696-704 ◽

Cited By ~ 45

Author(s):

D. M. Gray ◽

R. J. Granger

Keyword(s):

Soil Moisture ◽

Moisture Transfer ◽

Freezing Point ◽

Frozen Soil ◽

Vapor Flow ◽

Silty Clay ◽

Upward Movement ◽

Silt Loam ◽

Freezing Front ◽

Ice Content

The paper presents the results of field studies on the movement of moisture and salts during freezing of Prairie soils. It is shown that large fluxes of water can migrate to the freezing front and move upward into the frozen soil above. The fluxes are largest in light-textured soils (e.g., silt loam) having a water table at shallow depth. However, substantial amounts of soil moisture may also move in silty clay, silty clay loam, and clay soils under dryland farming provided there is sufficient water present to support capillary flow.The dynamics of soil moisture transfer under natural conditions as a result of freezing involves movement of water in both vapor and liquid phases. In the shallow surface layer of soil, to a depth of 300–400 mm, vapor flow predominates; in the depth below, water usually moves primarily as a liquid. It is demonstrated that the accumulation of ice with time increases because of the downward movement of the freezing front and the upward movement of water into the frozen soil above. In a silt loam with large fluxes, the ice content of the frozen zone rapidly reaches a level (80–85% pore saturation) where measurable migration ceases. Conversely, in a silty clay the movement of moisture into the frozen soil is observed to continue throughout most of the freezing period, and the ice content reaches 93% pore saturation. The greater movement in the finer grained soil is attributed to a higher freezing-point depression, a larger number of capillary pores, and a higher concentration of soluble salts in the liquid films.A close association is observed between changes in the ice content and electrical conductivity of a silt loam after freezing. In a silty clay the agreement is less clear, probably the result of the exchange of ions between the migrating liquid water and the clay particles. Maximum amounts of exchangeable ions moving into a 1 m depth of soil by the freezing action are estimated to be 11.9 t/ha in a silt loam and 15.7 t/ha in a silty clay loam.Data showing the redistribution of water and salts during thawing are also presented and discussed.

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Theoretical study of thermal damage in frozen soil

Thermal Science ◽

10.2298/tsci1504419z ◽

2015 ◽

Vol 19 (4) ◽

pp. 1419-1422

Author(s):

Zhi-Wu Zhu ◽

Yue Ma ◽

Zhi-Jie Liu

Keyword(s):

Dynamic Model ◽

Thermal Damage ◽

Theoretical Study ◽

Volumetric Strain ◽

Frozen Soil ◽

Ice Content

The weakened strength of frozen soil caused by rising temperature can result in thermal damage, which is mainly affected by ice content. A dynamic model for frozen ice is proposed considering temperature and volumetric strain.

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A Freezing-Thawing Damage Characterization Method for Highway Subgrade in Seasonally Frozen Regions Based on Thermal-Hydraulic-Mechanical Coupling Model

Sensors ◽

10.3390/s21186251 ◽

2021 ◽

Vol 21 (18) ◽

pp. 6251

Author(s):

Qingsong Deng ◽

Xiao Liu ◽

Chao Zeng ◽

Xianzhi He ◽

Fengguang Chen ◽

...

Keyword(s):

Rapid Development ◽

Coupling Model ◽

Frozen Soil ◽

Mechanical Coupling ◽

Damage Area ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Ice Content ◽

Ice Water

Seasonally frozen soil where uneven freeze–thaw damage is a major cause of highway deterioration has attracted increased attention in China with the rapid development of infrastructure projects. Based on Darcy’s law of unsaturated soil seepage and heat conduction, the thermal–hydraulic–mechanical (THM) coupling model is established considering a variety of effects (i.e., ice–water phase transition, convective heat transfer, and ice blocking effect), and then the numerical solution of thermal–hydraulic fields of subgrade can be obtained. Then, a new concept, namely degree of freeze–thaw damage, is proposed by using the standard deviation of the ice content of subgrade during the annual freeze–thaw cycle. To analyze the freeze–thaw characteristics of highway subgrade, the model is applied in the monitored section of the Golmud to Nagqu portion of China National Highway G109. The results show that: (1) The hydrothermal field of subgrade has an obvious sunny–shady slopes effect, and its transverse distribution is not symmetrical; (2) the freeze–thaw damage area of subgrade obviously decreased under the insulation board measure; (3) under the combined anti-frost measures, the maximum frost heave amount of subgrade is significantly reduced. This study will provide references for the design of highway subgrades in seasonally frozen soil areas.

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Performance of Highway Embankments in the Arctic Corridor Constructed under Winter Conditions

Canadian Geotechnical Journal ◽

10.1139/cgj-2019-0121 ◽

2020 ◽

Author(s):

Earl Marvin De Guzman ◽

Marolo Alfaro ◽

Guy Doré ◽

Lukas U. Arenson ◽

Aron Piamsalee

Keyword(s):

Performance Test ◽

Frozen Soil ◽

The Arctic ◽

Side Slope ◽

Displacement Sensors ◽

Fill Material ◽

Analysis And Synthesis ◽

Thaw Depth ◽

Ice Content ◽

Bottom Portion

There are uncertainties related to the mechanical behaviour of embankments where frozen soil is used as fill material and experience natural thawing and settlements during the first thawing season following construction. Fill material of embankments in the Arctic are primarily sourced from locally-available borrow sites which, in certain areas, are predominantly composed of fine till with high ground ice content. Side slope sloughing and fill cracking typically occur due to thawing of the frozen soil and development of localized thaw settlements under the embankment shoulders and side slopes. To assess a frozen fill embankment performance, test sections were constructed along the Inuvik-Tuktoyaktuk Highway in the Northwest Territories, Canada and instrumented with temperature and displacement sensors. One test section was reinforced with layers of wicking woven geotextiles at its side slopes to primarily provide reinforcement against lateral movements and drainage during the thawing season. Field data show that the central and bottom portion of the embankment fill is still frozen while the thaw depth has increased at the toe. This paper presents the analysis and synthesis of the first three-year monitored performance of the embankment test sections following construction.

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Analysis on Unfrozen Water Content of Mohe Permafrost Based on NMR Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.1185 ◽

2014 ◽

Vol 881-883 ◽

pp. 1185-1188

Author(s):

Hao Lin Yu ◽

Wei Wang ◽

Yuan Shun Ma ◽

Xue Yan Xu

Keyword(s):

Water Content ◽

Bound Water ◽

Free Water ◽

Physical And Mechanical Properties ◽

Frozen Soil ◽

Unfrozen Water ◽

Nmr Method ◽

Unfrozen Water Content ◽

Ice Content ◽

Function Relationship

Unfrozen water content has an important influence on the physical and mechanical properties of frozen soil. Little research has been done on unfrozen water content of permafrost in the Northeast Region, China, so the experimental investigation was performed on Mohe permafrost (4 kinds of samples were taken from 4 kinds of undisturbed frozen soil) based on NMR method, and the relationship and between frozen temperatures (-1°C, -4°C, -7°C, -11°C, -14°C, -16°C) and unfrozen water content was obtained. The test results indicate that, Unfrozen water content decreased with the reduction of frozen temperature of permafrost and there was a power function relationship between unfrozen water content and frozen temperature. The unfrozen water content reduction of No.3 sample was the slowest, because it had the lowest water content and the least frost-heave and thawed amount. It also can be attained that ice content of Mohe permafrost became more and more, but bound water and free water content got less and less while frozen temperature fell continuously.

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Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Journal of Hydrometeorology ◽

10.1175/jhm538.1 ◽

2006 ◽

Vol 7 (5) ◽

pp. 937-952 ◽

Cited By ~ 248

Author(s):

Guo-Yue Niu ◽

Zong-Liang Yang

Keyword(s):

Thermal Properties ◽

Soil Water ◽

Liquid Water ◽

Water Storage ◽

Frozen Soil ◽

Soil Water Storage ◽

Continental Scale ◽

Community Land Model ◽

Wide Range ◽

Ice Content

Abstract The presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite this important role, many recent studies show that explicitly including the hydrologic effects of soil ice in land surface models degrades the simulation of runoff in cold regions. This paper addresses this dilemma by employing the Community Land Model version 2.0 (CLM2.0) developed at the National Center for Atmospheric Research (NCAR) and a simple TOPMODEL-based runoff scheme (SIMTOP). CLM2.0/SIMTOP explicitly computes soil ice content and its modifications to soil hydrologic and thermal properties. However, the frozen soil scheme has a tendency to produce a completely frozen soil (100% ice content) whenever the soil temperature is below 0°C. The frozen ground prevents infiltration of snowmelt or rainfall, thereby resulting in earlier- and higher-than-observed springtime runoff. This paper presents modifications to the above-mentioned frozen soil scheme that produce more accurate magnitude and seasonality of runoff and soil water storage. These modifications include 1) allowing liquid water to coexist with ice in the soil over a wide range of temperatures below 0°C by using the freezing-point depression equation, 2) computing the vertical water fluxes by introducing the concept of a fractional permeable area, which partitions the model grid into an impermeable part (no vertical water flow) and a permeable part, and 3) using the total soil moisture (liquid water and ice) to calculate the soil matric potential and hydraulic conductivity. The performance of CLM2.0/SIMTOP with these changes has been tested using observed data in cold-region river basins of various spatial scales. Compared to the CLM2.0/SIMTOP frozen soil scheme, the modified scheme produces monthly runoff that compares more favorably with that estimated by the University of New Hampshire–Global Runoff Data Center and a terrestrial water storage change that is in closer agreement with that measured by the Gravity Recovery and Climate Experiment (GRACE) satellites.

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Feasibility study for a multi-level pore water pressure monitoring system using FBG sensors

Proceedings of 2005 IEEE/LEOS Workshop on Fibres and Optical Passive Components, 2005. ◽

10.1109/wfopc.2005.1462161 ◽

2005 ◽

Cited By ~ 1

Author(s):

S. Takeuchi ◽

Y. Kashiwai ◽

Y. Hirata ◽

Y. Yoshida ◽

M. Nishigaki

Keyword(s):

Monitoring System ◽

Pore Water ◽

Feasibility Study ◽

Pore Water Pressure ◽

Water Pressure ◽

Pressure Monitoring ◽

Fbg Sensors ◽

Multi Level

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Fracture toughness of frozen base and subbase soils in pavement

Canadian Geotechnical Journal ◽

10.1139/t01-032 ◽

2001 ◽

Vol 38 (5) ◽

pp. 967-981 ◽

Cited By ~ 8

Author(s):

Jean-Marie Konrad ◽

Julie Cummings

Keyword(s):

Fracture Toughness ◽

Frozen Soil ◽

Test Method ◽

Moisture Distribution ◽

Crushed Stone ◽

Base Layer ◽

Frozen Sand ◽

Average Grain Size ◽

Pavement Structure ◽

Ice Content

Temperature distribution in the pavement structure, moisture distribution in granular soils, modulus of the asphalt concrete, and fracture toughness of material in the pavement structure strongly influence the propagation and spacing of thermal contraction cracks. Fracture toughness was determined for frozen sand (subbase layer) and frozen crushed stone (base layer) by adapting established fracture mechanics test procedures recommended in American Society for Testing and Materials standard test method E399-83 for metals. It was established that fracture toughness increases with decreasing temperature and increasing volumetric ice content. For a temperature of 5°C, the fracture toughness of frozen crushed stone increased almost linearly from 0.05 to 0.40 MPa·m0.5 when the volumetric ice content increased from 6 to 14%. For frozen sand, the fracture toughness KIC in a wedge-opening mode increased from 0.04 to 0.70 MPa·m0.5 when the volumetric ice content increased from 8 to 28%. It was also established that the fracture toughness of frozen soil decreases with decreasing soil average grain size according to a logarithmic law.Key words: fracture, toughness, experimental, frozen, granular soil, pavement.

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