• Title/Summary/Keyword: heave rate

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Evaluation of Frost Heave Prediction and Frost Susceptibility in Sample using JGS Test Method (일본 동상성판정기준을 적용한 시료의 동상예측 및 동상성 평가)

  • Kim, Young-Chin;Hong, Seung-Seo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.926-931
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    • 2008
  • This paper show two different standardized test methods(Japanese Geotechnical Society; JGS 2003). One test is a "Test Method for Frost Heave Prediction Test, JGS 0171-2003", and the other test is a "Test Method for Frost Susceptibility, JGS 0172-2003". The purpose of this test is to obtain the freezing rate(freezing speed), frost heave ratio(heave to sample height), frost heave rate(heaving speed), and other parameters to be used for frost heave prediction and determine the frost susceptibility by freezing test with water intake. This method shall be used to predict the frost heave in frozen ground and evaluate the frost susceptibility of natural and replacement materials.

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Experimental Assessment and Specimen Height Effect in Frost Heave Testing Apparatus (동상시험장비의 실험적 검증 및 시료크기의 영향에 관한 연구)

  • Jin, Hyunwoo;Ryu, Byunghyun;Lee, Jangguen
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.1
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    • pp.67-74
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    • 2019
  • Frost heave is one of the representative engineering characteristics in cold regions. In South Korea, which is located in seasonal frost area, structural damage caused by frost heave and thaw happens and the need for research on the frost heave is increasing. In this paper, newly developed transparent temperature-controllable cell is used to focus on the frost heave. Frost susceptible artificial soil is used to analyze water intake rate which is one of the important factors in frost susceptibility criteria. Frost heave rate and water intake rate have similar behavior after heave by freezing of pore water converges. O-ring installed in the upper pedestal to measure water intake rate generates side friction between the inner wall of the freezing cell and O-ring, thereby hindering frost heave. Therefore, the frost susceptibility criteria using the water intake rate is not reliable. It is appropriate to use frost heave rate which has similar behavior with water intake rate. Frost heave tests were performed under two different specimen heights. Overburden pressure, temperature gradient and dry unit weight were set under similar state. Based on laboratory testing results, frost heave is independent on the specimen height.

Experimental assessment of the effect of frozen fringe thickness on frost heave

  • Jin, Hyun Woo;Lee, Jangguen;Ryu, Byun Hyun;Shin, Yunsup;Jang, Young-Eun
    • Geomechanics and Engineering
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    • v.19 no.2
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    • pp.193-199
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    • 2019
  • A frozen fringe plays a key role in frost heave development in soils. Previous studies have focused on the physical and mechanical properties of the frozen fringe, such as overall hydraulic conductivity, water content and pore pressure. It has been proposed that the thickness of the frozen fringe controls frost heave behavior, but this effect has not been thoroughly evaluated. This study used a temperature-controllable cell to investigate the impact of frozen fringe thickness on the characteristics of frost heave. A series of laboratory tests was performed with various temperature boundary conditions and specimen heights, revealing that: (1) the amount and rate of development of frost heave are dependent on the frozen fringe thickness; (2) the thicker the frozen fringe, the thinner the resulting ice lens; and (3) care must be taken when using the frost heave ratio to characterize frost heave and evaluate frost susceptibility because the frost heave ratio is not a normalized factor but a specimen height-dependent factor.

Development of experimental apparatus to evaluate frost heave and pressure (토사의 동상량 및 동상력 측정을 위한 실내 실험장치 개발)

  • Ko, Sung-Gyu;Choi, Chang-Ho;Chae, Jong-Gil
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09b
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    • pp.131-137
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    • 2010
  • `Frost heave' is volumetric extension behavior of soil due to freezing. It could have a bad effect to foundations of infrastructures like building, road, railroad and bridge. Therefore, it is considered as a primary design parameter with 'adfreeze bond' and 'creep deformation' for foundation design in cold region. In some countries, studies for analyzing frost heave in many ways have being performed, however, only a few studies for evaluating frost susceptibility of soils by measuring frost heave rate of frozen soils in Korea. For analyzing frost heave as a foundation design parameter, both frost heaving rate and heaving pressure are should be addressed in study. Hence, in this study, development of experimental apparatus to evaluate frost heave and pressure is suggested.

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Investigation of the ASTM International frost heave testing method using a temperature-controllable cell

  • Hyunwoo, Jin;Jangguen, Lee;Byung-Hyun, Ryu
    • Geomechanics and Engineering
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    • v.31 no.6
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    • pp. 583-597
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    • 2022
  • Frost heave can cause uneven ground uplift that may damage geo-infrastructure. To assist damage-prevention strategies, standard frost heave testing methods and frost susceptibility criteria have been established and used in various countries. ASTM International standard testing method is potentially the most useful standard, as abundant experimental data have been acquired through its use. ASTM International provides detailed recommendations, but the method is expensive and laborious because of the complex testing procedure requiring a freezing chamber. A simple frost heave testing method using a temperature-controllable cell has been proposed to overcome these difficulties, but it has not yet been established whether a temperature-controllable cell can adequately replace the ASTM International recommended apparatus. This paper reviews the applicability of the ASTM International testing method using the temperature-controllable cell. Freezing tests are compared using various soil mixtures with and without delivering blow to depress the freezing point (as recommended by ASTM International), and it is established that delivering blow does not affect heave rate, which is the key parameter in successful characterization of frost susceptibility. As the freezing temperature decreases, the duration of supercooling of pore water shortens or is eliminated; i.e., thermal shock with a sufficiently low freezing temperature can minimize or possibly eliminate supercooling.

Analysis of Hydraulic-Pneumatic System for Offshore Plant Heave Compensator (해양플랜트용 수직 보상기의 유공압 시스템 해석)

  • Jung, Yong-Gil;Hwang, Sung-Gu;Kim, Gwi-Nam;Yoon, Yung-Hwan;Hyun, Jang-Hwan;Huh, Sun-Chul
    • Journal of Power System Engineering
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    • v.19 no.1
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    • pp.76-82
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    • 2015
  • An analysis model is developed using a commercial software 'simulationX' for designing hydraulic-pneumatic system of heave compensator for offshore drilling operations. Reliability verification of the analysis model for the test equipment of 1/5 scale compensator was conducted by comparing test results and simulation results. An analysis of full scale heave compensator is developed on the basis of verified a model. Then, the results of simulation were analyzed to obtain following conclusion. The displacement of crown block about excitation input amplitude (${\pm}3,000mm$) of the steward platform using a 'simulationX' is attenuated under ${\pm}35mm$, and the compensation rate is 98.7%. In this study, goal of a compensation rate is more than 95%. The previously results are satisfied with the objectives of compensation rate.

Experimental Evaluation on JGS Frost Susceptibility Testing Method (일본 동상민감성 판정 기준에 관한 고찰)

  • Jangguen Lee;Hyunwoo Jin;Zheng Gong
    • Journal of the Korean GEO-environmental Society
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    • v.25 no.7
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    • pp.21-27
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    • 2024
  • Frost heave, a significant engineering aspect of frozen ground, leads to various damages in Korea during the winter. Both the United States and Japan, encompassing regions with frozen ground, have actively researched frost heave and possess standardized experimental methods. Particularly, the Japanese Geotechnical Society (JGS) has introduced a frost heave standard testing method, offering the advantage of relatively simple specimen preparation and experimental procedures. However, issues persist regarding the ambiguous engineering interpretation of frost heave test results and the lack of clear criteria for frost heave susceptibility assessment. This paper presents laboratory testing results following the JGS testing method on sand and silt mixtures using a triaxial temperature-controllable cell, and thoroughly analyzes the frost heave rate calculation process. Furthermore, it evaluates the applicability of frost heave susceptibility criteria proposed in the United States to frost heave rates based on the JGS testing method.

Frost Heave of Frost Susceptible Soil According to Performance of Thermo-syphon (열 사이펀 성능에 따른 동상민감성 지반의 거동 비교)

  • Park, Dong-Su;Shin, Mun-Beom;Seo, Young-Kyo
    • Journal of the Korean Geotechnical Society
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    • v.37 no.10
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    • pp.27-40
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    • 2021
  • The construction method to prevent the frost heave or thaw settlement is called the ground stabilization method, and the thermo-syphon is one of the typical ground stabilization methods. The thermo-syphon has recently been developed with a simple analysis model and thermal analysis has been carried out, but the frost heave of frost susceptible soil was not considered. This study was conducted using ABAQUS internal user subroutine to develop the numerical analysis model (Coupled thermo-mechanical) that can simultaneously perform thermal analysis for the temperature change of the soil according to the thermo-syphon and structural analysis to predict the frost heave of the soil accordingly. As a result of the numerical analysis, the frost heave of the soil decreased as the performance of the thermo-syphon increased. As for the main results, when the thermo-syphon which has contain 25%, 50%, and 100% of refrigerant filling ratio was applied, the reduction ratio of the frost heave was 5.5%, 14.4%, and 21% respectively.

Influencing Factors on Freezing Characteristics of Frost Susceptible Soil Based on Sensitivity Analysis (민감도 분석을 기반으로 한 시료의 동결 특성에 미치는 영향인자 분석)

  • Go, Gyu-Hyun;Lee, Jangguen;Kim, Minseop
    • Journal of the Korean Geotechnical Society
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    • v.36 no.8
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    • pp.49-60
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    • 2020
  • A fully coupled thermo-hydro-mechanical model is established to evaluate frost heave behaviour of saturated frost-susceptible soils. The method is based on mass conservation, energy conservation, and force equilibrium equations, which are fully coupled with each other. These equations consider various physical phenomena during one-dimensional soil freezing such as latent heat of phase change, thermal conductivity changes, pore water migration, and the accompanying mechanical deformation. Using the thermo-hydro-mechanical model, a sensitivity analysis study is conducted to examine the effects of the geotechnical parameters and external conditions on the amount of frost heave and frost heaving rate. According to the results of the sensitivity analysis, initial void ratio significantly affects each objective as an individual parameter, whereas soil particle thermal conductivity and temperature gradient affect frost heave behaviour to a greater degree when applied simultaneously. The factors considered in this study are the main factors affecting the frost heaving amount and rate, which may be used to determine the frostbite sensitivity of a new sample.

A Thermodynamic Study on Freezing Characteristics of Weathered Tuff Soil- Freezing Point Depression with the Variation of Overburden Pressure - (응회암 풍화토의 동결특성에 관한 열역학적 연구-상재하중과 동결점 저하를 중심으로-)

  • 서상열
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.297-306
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    • 1999
  • In this research, the frost heave mechanism of the weathered tuff soil sampled from the area tying between Ulanbator and Beijing was studied. The frost heave tests were carried maintaining the constant temperature at both upper$(+5^{\circ}C)\; and\; lower(-5^{\circ}C)$ ends of the sample. Here, main emphasis is given on variation of the freezing point depression with the variation of applied overburden pressure. The expansion of ice lens and migration of the pore water towards freezing front were observed in the test. It was found that with the increase in overburden pressure there is decrease in heave rate and increase in the absolute value of a segregation-freezing temperature. Hence the equation between segregation-freezing temperature and overburden pressure could be suggested. Also the water content of the samples at the frozen side was shown to be higher than those at the unfrozen side. Similarly, the water at warmer part of the frozen tuff was found much higher than that of the cooler part.

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