• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.109-121
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• 2012

Rock-surface temperatures were observed at a trachytic lava dome, called as Baeknokdam Northwest Face, in the summit area of Mt. Halla, Jeju Island, to examine the frequency and occurrence season of freeze-thaw cycles and the rate of temperature changes during a freezing period. Long-term measurements were recorded over 18 months from November 2006 to April 2008, at a 1-hour logging interval and rock depth of 1.5 cm. Both diurnal freeze-thaw cycles and effective freeze-thaw cycles appear in larger numbers on a south-facing rock face than a north-facing rock face. The diurnal cycles were dominantly observed on February and March for the south face and on November and April for the north face, respectively. The annual freeze-thaw cycles were confirmed in terms of the presence of seasonal freezing periods lasting from mid-November to mid-April for the south face and from early-November to late-April for the north face, respectively. The rate of decreasing temperatures during the seasonal freezing periods is larger on the north face than the south face. Notwithstanding the lower numbers of freeze-thaw events, the north face experiences a higher frost intensity since the number of hours below $-3^{\circ}C$ is larger on the north face than the south face. The number of freeze-thaw events and the duration of days with continuous sub-zero rock temperatures largely depend on the solar radiation controlled by the aspect of the monitored rock surfaces, and thus the high-frequency short-term frost cycle dominantly appears on the south face and the annual frost cycle on the north face, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.433-439
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• 2011

The frost depth(frost penetration) is used to install anti-frost heave layers in pavement designs. The freezing index is calculated by an annual accumulated value of multiplying the period of time with temperatures below zero, and the corresponding temperature. Therefore, the DAAT(daily average air temperature) calculation method may play an effect on the FI(freezing index). The Weather Observatory used to supply 4 average air temperatures per day, but currently supplies 8 per day. With this study, we divided the southern part(below FI=$350^{\circ}C{\cdot}day$) of the Korean peninsula into 6 areas according to site conditions(low embankment, embankment-cutting slope, and the cutting slope) and established a field measurement system for 15 positions to check the effects on the result of FI according to differing DAAT calculation methods. The air temperatures obtained by the field measurement system was used to calculate and compare the FI. As a result, the freezing index calculated based on the $DAAT_4(T_4)$ is normally greater by 3% than the one on $DAAT_8(T_8)$. In addition, the calibration equation for the freezing index using air temperatures was proposed through the research.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.31-40
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• 2022

Recently, the Arctic resource development project, where undeveloped energy resources (oil, natural gas, etc.) are deposited, is actively being promoted for the perspective of diversifying the construction market and developing future energy resources. However, the frozen ground always has problems such as sinking and frost-heaving due to extreme weather. Therefore, it is necessary to analyze the thermal characteristics of the frozen soil to secure the stability of the ground structure. In this study, a series of laboratory tests were performed to evaluated the thermal characteristics of frozen soil samples in the oil sand field in Alberta, Canada. In additon, it was compared with the results of domestic(Gangwond-do) sample performed under the same conditions. As a comparison results of the experiments, it was clarified that the different frozen water content and thermal conductivity characteristics by temperature after completion of freezing could affect the frozen soil behavior.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.205-212
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• 1998

Frost damage of a storage tank for chemical admixtures caused by a low temperature in winter and quality deterioration of chemical admixtures have been often reported. However, there have been few regulations and researches related to the frost damage of chemical admixtures and facilities. Therefore, this paper is intend to investigate not only, the freezing points of chemical admixtures such as AE admixtures and water-reducing AE admixtures, etc., but also the quality variation of concrete used with chemical admixtures before freezing and after freeze-thaw cycles. According to the results of experiments, most chemical admixtures except anti-freezing agent and accelerating water-reducing AE admixtures should be kept from being frozen in low winter temperatures. However, full agitation of frozen chemical admixtures dose not cause the problems of concrete related to the quality of chemical admixtures.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.75-84
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• 2013

Soil freezing is a phenomenon arising due to temperature difference between atmosphere and ground, and physical properties of soils vary upon the phase change of soil void from liquid to solid (ice). A heat-transfer mechanism for this case can be explained by the conduction in soil layers and the convection on ground surface. Accordingly, the evaluation of proper thermal properties of soils and the convective condition of ground surface is an important task for understanding freezing phenomenon. To describe convection on ground surface, simplified coefficient methods can be applied to deal with various conditions, such as atmospheric temperature, surface vegetation conditions, and soil constituents. In this study, two methods such as n-factor and convection coefficient for the convective ground surface boundary were applied within a commercial numerical program (TEMP/W) for modeling soil freezing phenomenon. Furthermore, the numerical results were compared to laboratory testing results. In the series of the comparison results, the convection coefficient is more appropriate than n-factor method to model the convective boundary condition.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.81-92
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• 2013

This paper presents the results of a numerical investigation into the behavior of retaining wall subject to cycles of freezing and thawing due to seasonal temperature change. The thermo-hydro-mechanical coupled finite element modeling strategy was first established to simulate the wall behavior. A series of finite element analyses were then performed on a range of conditions representing seasonal temperature change characteristics. The results indicated that the average freezing temperature and the number of cycles of freezing and thawing were the primary influencing factors for the wall behavior. Also revealed was that the duration of freezing period does not significantly affect the wall displacement and the lateral earth pressure, and that the earth pressure on the wall does not significantly change due to the freezing and thawing action suggesting that the increase in the wall displacement during the freezing and thawing action may be attributed to degradation of backfill due to the freezing and thawing action.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.213-218
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• 1992

The reaching time to the freezing point was to be fast in the order of 2% agar gel, 5% agar gel, 20% gelatin gel, pork, respectively. The freezing time and the passing time through the zone of the maximum ice crystal formation had linear relationship with the coolant temperature. The average diameter d$_{p}$ of ice crystal in a soybean protein gel and the moving of freezing front were represented an inverse proportion, and the moving velocity of freezing front was shown as 3.4$\times$10$^{-6}$ $\textrm{cm}^2$/sec from predicted theoretical formula. This value was very close to experimental results. The storage temperature did not give any influences for the growth of ice crystal in inside soybean protein gels during freezing conservation. The relationship between freezing condition and structure of freezing front was as follows : (moving velocity of freezing front) : (mass transfer rate of water at freezing point)$\times$(surface area of freezing front).

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.71-79
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• 2010

The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system test simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the road structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this Paper, the evaluation of frost susceptibility was conducted by means of the mechanical property test and laboratory freezing system apparatus. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade soils of highway construction site, were measured to determine the frost susceptibility.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.401-412
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• 2016

It is extremely difficult to apply conventional grouting methods to subsea tunnelling construction in the high water pressure condition. In such a condition, the rapid artificial freezing method can be an alternative to grouting to form a watertight zone around freezing pipes. For a proper design of the artificial freezing method, the influence of salinity on the freezing process has to be considered. However, there are few domestic tunnel construction that adopted the artificial freezing method, and influential factors on the freezing of the soil are not clearly identified. In this paper, a series of laboratory experiments were performed to identify the physical characteristics of frozen soil. Thermal conductivity of the frozen and unfrozen soil samples was measured through the thermal sensor adopting transient hot-wire method. Moreover, a lab-scale freezing chamber was devised to simulate freezing process of silica sand with consideration of the salinity of pore-water. The temperature in the silica sand sample was measured during the freezing process to evaluate the effect of pore-water salinity on the frozen rate that is one of the key parameters in designing the artificial freezing method in subsea tunnelling. In case of unfrozen soil, the soil samples saturated with fresh water (salinity of 0%) and brine water (salinity of 3.5%) showed a similar value of thermal conductivity. However, the frozen soil sample saturated with brine water led to the thermal conductivity notably higher than that of fresh water, which corresponds to the fact that the freezing rate of brine water was greater than that of fresh water in the freezing chamber test.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.1-10
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• 2014

This paper presents the results of a field pilot test about deformation of water supply pipelines due to freezing temperature. There is a difference between for frost heaving load to act on the water supply pipelines. If the Marston-Spangler theory is only considered for the frost heaving load to act on the water supply pipeline, it is likely to deviate from the safety of the water supply pipeline, strains of the water supply pipeline show a tendency of smaller value than the value of numerical analysis.