• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.451-458
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• 2004

The study was focused on the development of computational scheme in three dimensional configurations by applying effective heat capacity model to the numerical procedure in order to predict the temperature profiles of a buried pipeline and the frozen penetration depth(FPD) of a freezing soil medium. To realize this, the investigator conducted the unsteady state heat transfer analysis, using the commercial code ABAQUS, for the freezing granite soil medium including a pipeline in a closed system. The proposed model took into consideration the phase change effect of in situ pore water in the frozen fringe. The comparison of results obtained by the proposed model and the actual performances was valuable in establishing a level of confidence in the application of introduced theory.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.219-228
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• 2003

Numerical and experimental studies were conducted on the temperature distribution of a buried steel pipe and surrounding granite frozen soils in the closed system. The relationship between unfrozen water content and temperatures was analysed by laboratory test. The thermal conductivity measurements were made to compare the results with a formula presented by Lachenbruch. A steel container model that consists of a freezing chamber and a buried circular steel pipe was built for the laboratory temperature measurements. The time temperature records were measured experimentally, and those records were compared with numerical results obtained from FEM analysis in order to verify the feasibility. The latent heat effect on the granite frozen soils in the numerical study was considered.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.51-60
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• 2012

In order to characterize the shear strength of the frozen sand for foundation design in cold region and prediction of adfreeze bond strength, many researchers developed test techniques and carried out many tests to analyze shear strength properties of the frozen sand for half a century. However, many studies for shear strength properties of the frozen sand have been carried out with limited circumstances, even though shear strength of the froze sand can be affected by various influence factors such as soil type, temperature conditions, and magnitude of normal stress. In this study, direct shear test equipment was used to analyze the shear strength characteristics of the frozen sand. Direct shear test equipment was designed for cold weather, and the direct shear tests were carried out inside of large-scaled low temperature chamber. Three soil types-two uniform sands and one well graded soil were used to analyze the shear strength of the frozen sand with three different temperature conditions and three different vertical confining pressures. In this research, a series of direct shear tests for shear strength of the frozen sand have been conducted to demonstrate the efficiency of effectiveness of the test equipment and low temperature chamber. This research also showed that shear strength of the froze sand increased with decreasing temperature condition, but the influence of vertical confining pressure was insignificant to the shear strength of the frozen sand.

• Journal of the Korean GEO-environmental Society
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• v.14 no.12
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• pp.23-30
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• 2013

Bearing capacity of pile is governed by only skin friction in frozen ground condition, while it is generally governed both by skin friction and end bearing capacity in typically unfrozen ground condition. Skin friction force, which arises from the interaction between pile and frozen soils, is defined as adfreeze bond strength, and adfreeze bond strength is one of the most important key parameters for design of pile in frozen soils. Many studies have been carried out in order to analyze adfreeze bond strength characteristics over the last fifty years. However, many studies for adfreeze bond strength have been conducted with limited circumstances, since adfreeze bond strength is sensitively affected by various influence factors such as intrinsic material properties, pile surface roughness, and externally imposed testing conditions. In this study, direct shear test is carried out inside of large-scaled freezing chamber in order to analyze the adfreeze bond strength characteristics with varying freezing temperature and normal stress. Also, the relationship between adfreeze bond strength and shear strength of the frozen soil obtained from previous study was analyzed. The coefficient of adfreeze bond strength was evaluated in order to predict adfreeze bond strength based on shear strength, and coefficients suggested from this and previous studies were compared.