• Title/Summary/Keyword: Frost Heaving

Search Result 51, Processing Time 0.025 seconds

Effects of Freezing a Backfill Material under Undrained Condition on a Buried Pipe (포화 사질토 뒷채움재의 비배수 동결에 의한 매설 강관의 거동 - 실대형 모형실험 연구 -)

  • Kang, Jae-Mo;Lee, Jang-Guen;Kim, Hak-Seung;Lee, Sang-Yoon;Ryu, Byung-Hyun;Cho, Nam-Jun
    • Journal of the Korean Geotechnical Society
    • /
    • v.30 no.8
    • /
    • pp.39-47
    • /
    • 2014
  • Frost heaving and thawing settlement cause unexpected stress around buried pipelines, which results in deformation and permanent demage. A large scale laboratory test has been performed to observe deformation, stress, and temperature of a buried pipe during atmospheric temperature changes. From the experimental results, the stress concentrated around the buried pipe is inevitable and deformation is caused by the frost heaving. Even though backfill materials are sandy soils which are normally assumed to be non frost susceptible, it is revealed that frost demage can happen due to drainage condition, the level of ground water table, and water content.

Behavior Characteristics of Water Supply Pipeline Due to Freezing Temperature (동결온도가 상수도관의 거동에 미치는 영향)

  • Shin, Eun Chul;Ryu, Byung Hyun;Kang, Hyoun Hoi;Hwnag, Soon Gab
    • Journal of the Korean Geosynthetics Society
    • /
    • v.13 no.4
    • /
    • pp.1-10
    • /
    • 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.

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
    • /
    • 2000.03b
    • /
    • pp.548-555
    • /
    • 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.

  • PDF

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
    • /
    • 2008.03a
    • /
    • pp.926-931
    • /
    • 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.

  • PDF

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
    • /
    • v.36 no.8
    • /
    • pp.49-60
    • /
    • 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.

The Frost Heaving Susceptibility Evaluation of Subgrade Soils Using Laboratory Freezing System (실내 동상시스템을 이용한 노상토의 동상민감성 평가)

  • Shin, Eun Chul;Ryu, Byung Hyun;Park, Jeong Jun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.12 no.2
    • /
    • pp.13-23
    • /
    • 2013
  • The Korean Peninsula is considered as a seasonal frozen area that is thawed in the spring and frozen in the winter. The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing tests 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 geotechnical 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 this study, ten soil samples are prepared. The basic physical property tests were performed by following the Korean Industrial Standard and the soil specimens were classified by the Unified Soil Classification System (USCS). These classified soils are used to perform the laboratory opened systems freezing test in order to determine the frost heaving characteristics of soils such as unfrozen water content, heaving amount, and freezing depth.

Mechanical Behavior of Buried Pipe Line with Frost Prevention Materials (동상방지재료를 활용한 온도에 따른 매설관 거동 특성에 대한 연구)

  • Kang, Jae-Mo;Kim, Hak-Seung;Kim, Young-Seok;Lee, Jang-Keun;Hong, Sung-Seo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.09a
    • /
    • pp.546-552
    • /
    • 2010
  • Seasonal frozen ground affects structural behavior in South Korea. Frost and heaving of seasonal frozen ground results in the critical damage of roadway, railroad, and buried pipeline. It has been widely used to substitute frost susceptible soils with granular soils. This paper presents experimental investigation on the effectiveness of soil-shredded tire and soil-expanded polystylene (EPS) mixtures to reduce frost depth and force around a buried pipeline. Experimental data such as measured temperature profile and the deformation of buried pipeline were carefully observed and provide the evidence of the effectiveness of soil mixtures.

  • PDF

Evaluation of Freeze-Thaw Effect on the Modulus of Subgrade Soils from Impact Resonance Test (충격공진시험을 이용한 동결.융해에 따른 노상토의 탄성계수 평가)

  • Lee, Jae-Hoan;Kweon, Gi-Chul
    • International Journal of Highway Engineering
    • /
    • v.12 no.3
    • /
    • pp.71-77
    • /
    • 2010
  • Anti-freezing layer does not used in case of non frost heaving in subgrade soils. In this case, the modulus of subgrade soils were varied with freezing and thaw cycles under non frost heaving. That effect should be properly considered in pavement design. Impact resonance test that is nondestructive testing method was used for continuously determining the modulus of subgrade soils during freezing and thaw cycle. The modulus of subgrade soils was identical with freezing and thaw cycles under closed freezing and thaw system which is no water supplement into specimen during testing. There was also no difference in the modulus of subgrade soil between before and after freezing-thaw cycles for all specimens with different water content and density. That is thaw-weakening of subgrade soils do not occur under closed freezing and thaw system. The moduli at freezing conditions are varied with water content and density, but it can be ignored in practical design sense.

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
    • /
    • v.11 no.3
    • /
    • pp.27-35
    • /
    • 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.

The Freezing Characteristics of Pavement Layer Using the Field Road Model Test (현장도로 모형실험을 이용한 포장구성층의 동결 특성 분석)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • Journal of the Korean Geotechnical Society
    • /
    • v.26 no.7
    • /
    • pp.71-80
    • /
    • 2010
  • Korea is considered to be a seasonal frozen soil area that thaws in the spring, and freezes in winter. In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by the depth frozen due to the temperature condition. Therefore, there is a tendency of over-design and applying uniform thickness without the consideration of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential to study the structural appropriateness of pavement layer and bearing capacity besides the seasonal and mechanical properties of pavement materials to take an appropriate and reasonable design of the road structure. In this paper, the evaluation of frost susceptibility on subgrade, ant-freezing layer, subbase was conducted by means of the mechanical characteristics and model experiment. The temperature, heaving amount, unfrozen water contents and freezing depth of soil samples, the subgrade, anti-freezing layer, subbase soils of road construction site were measured to determine the frost susceptibility.