• Title/Summary/Keyword: Frost heave amount

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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.

Field Model Tests on Frost Penetration Depths and Frost Heave Amounts in Ballast track and Concrete track (현장모형실험을 통한 자갈궤도와 콘크리트궤도의 동결심도 및 동상량 측정)

  • Kim, Young-Chin
    • Journal of the Korean Society for Railway
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    • v.19 no.4
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    • pp.506-514
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    • 2016
  • Experimental ballast track and concrete track were installed on the railway site and the frost penetration depth and the frost heave amount in the winter were measured. As a result, when the freezing index was the same, the frost penetration depth of concrete track was deeper than that of ballast track. Furthermore, when an XPS and polyethylene aggregate layer was installed below the ballast track, the frost penetration depth of the ballast track decreased significantly; in the case of the concrete track, the frost penetration depth decreased when the thickness of the subbase increased. Meanwhile, the frost heave amount also decreased when an XPS and polyethylene aggregate layer was installed below the ballast track ; in the case of the concrete track, the frost heave amount decreased when the thickness of the subbase increased.

Field Experiments for Reducing Frost Susceptibility Using Recycled Tire Powder (폐타이어 파우더 혼합이 동상억제에 미치는 영향에 관한 야외실험 연구)

  • Kim, Hak-Sam;Suzuki, Teruyuki;Fukuda, Masani;Seo, Sang-Youl;Yamashita, Satoshi
    • Journal of the Korean Geotechnical Society
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    • v.26 no.4
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    • pp.5-14
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    • 2010
  • Three years of frost heave field experiments were conducted to evaluate a method for reducing heave using a recycled tire powder-soil mixture. By mixing Tomakomai soil with 20% recycled tire powder, frost heave amount was drastically decreased. The results of the field experiment confirm that recycled tire powder is an excellent material for use in controlling the total amount of heave. The restraining effect of a recycled tire powder-soil mixture is qualitatively analyzed based on amount of frost heave, frost heave ratio, thermal conductivity, permeability and segregation potential theory.

The Control of the Ground Frost Heave by Using the Scrap Tire (폐타이어를 이용한 지반동상 방지)

  • 김영진;강병희
    • Geotechnical Engineering
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    • v.14 no.1
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    • pp.49-58
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    • 1998
  • It was investigated whether the scrap tire can be recycled as a construction material for controlling the frost heave of the ground. Some frost heave tests and a frost penetration depth test in the laboratory were performed on the weathered granite soil mitred with variable amount of scrap tire powder under the atmospheric temperature at -$17^{\circ}$ to find the basic effects of the scrap tire on the control of frost. The frost heave control layer of the crushed stone mixed with scrap tire chips directly below thin subbass in the bituminous pavement was found to be effective for practical use. And the equation for the required thickness of this frost heave control layer with freezing index was suggested.

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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.

An Experimental Study on the Waste Polyethylene Aggregate for Construction Materials (폐비닐 골재의 기본특성에 관한 연구)

  • Kim, Young-Chin
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.4
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    • pp.5-16
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    • 2003
  • The aggregate out of waste polyethylene was made in order to recycle waste polyethylene wasted in the country side. Many physical and mechanical experiments which include leaching test, specific gravity test, compaction test, LA abrasion test, large-scaled shear test, and permeability test were performed for the waste polyethylene aggregate. The thermal conductivity test, unfrozen water content test and frost heave test were also performed. The temperature distribution for both gravels and waste polyethylene aggregate, which were constructed in the frost heave layer in the field, was measured in winter season of continuous 2 years and compared.

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A Fundamental Study on the Waste Polyethylene Chips Mixed with Soil (폐비닐 골재 혼합토의 기본 성질에 관한 연구)

  • 김영진;김현민
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.548-555
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    • 2000
  • It was investigated whether the waste polyethylene chips can be recycled as construction materials in geotechnical engineering field. The standard Proctor test, the hydraulic conductivity test, the large box direct shear test, the thermal conductivity test, the frost heaving test and the time domain reflectometry test were performed on weathered granite soil mixed with variable amount of the waste polyethylene chips. The experimental results showed that the hydraulic conductivity and the shear strength of weathered granite soil increase with increasing the amount of the waste polyethylene chips. On the other hand, the thermal conductivity, the amount of frost heaving and the unfrozen water contents of weathered granite soil decrease with increasing the amount of the waste polyethylene chips.

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Geotechnical Characteristics of Frost-Susceptibility Soil Using Modified Freeze-Thaw Apparatus (변형된 동결-융해 시험장치를 이용한 동상민감성흙의 지반공학적 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.1
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    • pp.53-59
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    • 2009
  • A new system of modified freeze-thaw testing apparatus is introduced. This system is developed to evaluate the geotechnical parameters and their dependence upon freezing-thawing history of frost-susceptibility soil. A necessary condition for stationary frost heaving is clarified in this paper. The method changes the thermal boundary condition up to the net heat flow at the freezing frost becomes zero. The effectiveness of this method is verified by freeze-thaw tests. Frost heaving observed after the application of the method is found to be due to another frost heaving action called long-term frost heaving. This frost heaving has already been studied and is considered ignorable as engineering factor because of its small heaving amount.

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Freezing and Deflection Characteristics of Flexible Pavement Structure Using Frost Model Test (동상모형실험을 통한 아스팔트 포장체의 동결 및 처짐 특성)

  • Shin, Eun-Chul;Hwang, Soon-Gab;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.3
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    • pp.27-35
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    • 2012
  • In this paper, the frost heaving and thawing characteristics of flexible pavement structure were evaluated in the large scale freezer which have a specification of temperature range $-20^{\circ}C{\sim}10^{\circ}C$ and $3.2m(L){\times}3.2m(B){\times}2.4m(H)$ in size. The insulated steel box with the size of $0.9m(L){\times}0.9m(B){\times}0.9m(H)$ was used to simulate actual pavement road structure. The variation of temperature, frost heave amount and frost heave pressure were measured through the instrument of TDS-602 data logger. LFWD (light falling weight deflectometer) was used to determine the change of deflection due to the frost heaving and thawing. Furthermore, the influence of aggregate layer to the freezing of the subgrade soil was studied to verify the function and effectiveness of the anti-freezing layer.

Effect of XPS and Polyethylene Aggregates in Model Tests for Prevention of Frost Heave in Railroad Track (철도에서의 동상방지를 위한 모형시험에서 XPS 및 PE골재의 설치 효과)

  • Kim, Donggwan;Yoon, Yeowon;Kim, Youngchin
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.10
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    • pp.5-13
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    • 2014
  • In this research, in order to study insulation effect of commercial XPS and recycled PE aggregates for prevention of frost heave in the roadbed of railroad track from the freezing temperature, model tests were carried out in the large freezing room. For this, thermal conductivities were measured for various dry densities, water contents, temperatures and mixing ratios of PE aggregates. From the tests, it can be seen that thermal conductivities of roadbed decrease with the increase of the ratio of mixed PE aggregates. However it was sensitive to the changes of temperature and water content due to the amount of water in the voids. From the model test of railroad track, it can be seen that the time to reach $0^{\circ}C$ was longer for XPS than that for the PE aggregates. Also the test shows best insulation effect can be achieved when XPS board was installed above the PE aggregate layer rather than the opposite order.