• Title/Summary/Keyword: Granite soil

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Dynamic Characteristics of Decomposed Granite Soils by Changing Geoenvironment (지반환경 변화에 따른 화강토의 동적특성)

  • Lee, Jin-Soo;Lee, Kang-Il;Kim, Kyung-Jin
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.1
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    • pp.41-52
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    • 2014
  • Decomposed granite soil is likely to lose its strength when exposed to air or water. Such a geomaterial is weathered by wetting-drying or freezing-melting. In this study, resonant column tests were conducted to figure out the dynamic characteristics of granite soil that has affected by environmental changes like weathering condition. The results show that wetting-drying weathering condition is the most affective parameter on the dynamic characteristics of granite soil. In the meantime, artificial weathering conditions such as freezing-melting has less affection at first and getting increase as the process repeats constantly.

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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Analysis of Stress-Strain of Weathered Residual Granite Soil with Variation of the Initial Water Content (초기함수비 변화에 의한 풍화잔류토의 응력-변형률 해석)

  • 김찬기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.2
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    • pp.80-91
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    • 1999
  • This paper presents the stress-strain , volumetric strain characteristics of the Pocheon weathered residual granite soil with variation of the initial water content under drained conditions. A series of consolidated drained triaxial compressiion tests and isotrpc compression tests with various initial water content on specimens were performed. All material parameters of Lade's double work hardening model were determined by using the results of tests. Most aspects of the soil behavior measured in the triaxial compression tests were reproduced with good accuracy by the constitutive model . Therefore double work hardening model has been shown to be applicable to weathered residual granite soil.

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Comprarison of Yasufuku's Single Hardening Constitutice Model and Lade's Double Hardening Constitutive Model for Compacted Weathered Granite Soil (다짐화강토에 대한 Yasufuku 의 단일항복면 구성모델과 Lade의 복합항복면 구성모델의 비교)

  • 정진섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.3
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    • pp.91-100
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    • 1999
  • Tow constitutive models for weathered granite soil, Yasufuku's constitutive model with a single yield surface and Lade's constitutive model with two intersectiong yield surface compared in terms of their capabilities to accurately capture the observed behavior of compacted weathered grainite soil for various stress-paths. Both the single surface and the double surface models capture the experimentally observed behavior at a variety of stress-paths with good accuracy. The double surface model may model the observed compacted weathered granite soil behavior with better accuracy for proportational loading with increasing stress, but the single surface model may model dilatancy property with better accuracy for p-constant loading with increasing stress ratio.

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Characteristics of the transitional element contents for the ginsengs from the 3 different soils of Keumsan (금산의 서로 다른 3 토양내에 생육되는 인삼의 전이원소 함량 특성)

  • Song, Suck-Hwan;Min, Eil-Sik;Park, Gwan-Su;Yoo, Sun-Kyun
    • Journal of Ginseng Research
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    • v.29 no.4
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    • pp.192-205
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    • 2005
  • This study is for geochemical relationships between ginsengs and soils from three representative soil types from Keumsan, shale, phyllite and granite areas. For this study, ginsengs (2, 3 and 4 years), with the soils and their host rock, are collected and are analysed for the transitional elements. In the weathered soils, the shale area is high in the most of elements, but low in the granite area. High correlation relationships are shown in the shale area. In the field soils, the shale area is mainly high, but low in the granite area. Comparing with ages, most of elements are high in the 2 year soils, but low in the 4 year soils. Regardless of the localities, positive and negative correlations are dominant in the shale area. In the host rocks, high element contents are shown in the phyllite and shale areas. Positive and negative correlations are found in the shale and phyllite areas for large numbers of the element pairs. In the ginsengs, differences of the element contents with ages are not clear, but show high element contents in the 2 year ginsengs of the shale and phyllite areas, and low contents in the 4 year ginsengs of the granite area. Positive correlations are shown in the Cu-Zn pair in the shale and phyllite areas, and Co-Cu pair in the granite area. In the relative ratios(weathered soil/field soil), most of elements from the shale area are high, above I, suggesting high element contents in the weathered soils of the shale area relative to the granite and phyllite areas. In the relative ratios(weathered soil/host rock), most of elements are above 1, suggesting the high element contents in the weathered soils relative to the host rocks. Relative ratios (soil/ginseng) of the element contents are several to ten times. Regardless of the areas, big differences of the relative ratios are found in the Co and small differences are in the Cu and Zn, which suggest that differences between soils and ginsengs are big in the Co contents and small in the Cu and Zn contents. Regardless of the ages, differences among relative ratios are small in granite area relative to the shale area, which suggest more similar contents between ginsengs and soils in the granite areas.

Evaluation of pesticide residue analysis of dieldrin in soil using a high resolution gas chromatograph/mass spectrometer (HR-GC/MS)

  • Hwang, Jae-Bok;Park, Tae-Seon
    • Korean Journal of Agricultural Science
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    • v.43 no.4
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    • pp.634-640
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    • 2016
  • The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were $39.7ng\;g^{-1}$ and $40.51ng\;g^{-1}$, respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

A study on the Consolidation Characteristics of remolding Marine Clay and Weathered Granite Soil by SCT and CRSC (표준.일정변형률속도 압밀시험을 이용한 해성점토.화강암질 풍화토의 압밀특성에 관한 연구)

  • 기완서;주승완;김선학;심태섭
    • The Journal of Engineering Geology
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    • v.12 no.4
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    • pp.459-469
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    • 2002
  • We have remolded marine clay sample collected along the vertical and horizontal directions and investigated the characteristics of the consolidation constants by SCT and CRSC methods. We have studied also on consolidation chracteristics and application for weathered granite soil using SCT and CRSC methods for undisturbed and disturbed samples. As the result, values of pre-consolidation stress, compression index, excessive pore pressure, pore water pressure ratio of the marine-clay were different due to different test methods(SCT and CRSC) and sampling directions(vortical and horizontal directions). Disturbed and undisturbed samples of the weathered granite soil have showed similar change aspect like marine clay during over-consolidatied and normally consolidatied stages.

Dynamic Properties and Settlement Characteristics of Korea Weathered Granite Soils (화강풍화토의 동적 물성치와 침하특성에 대한 연구)

  • Park, Jong-Gwan;Kim, Yeong-Uk;Lee, In-Mo
    • Geotechnical Engineering
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    • v.9 no.2
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    • pp.5-14
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    • 1993
  • Weathered granite soil is the most representative as a surface soil in Korea. In this paper, the dynamic properties and settlement characteristics of Korea granite soil are studied through the dynamic triaxial compression tests. The dynamic characteristics are very important on the analysis of the foundations under dynamic loading such as machine vibration and earthquake. Soil samples having different grain sixtes were prepared at the relative densities between 80oA and 90oA and tested to measure shear moduli and damping ratios at each level of shear strain. The measured shear moduli of weathered granite soils showed large variations according to the grain sizes, confining pressures, relative densities and shear strains. Sandy weathered granite had a little larger dynamic properties than the average values of the sand studied by Seed and Idriss. Pot the well compacted granite soils, little residual settlements occured due to dynamic loading.

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Estimation of saturated hydraulic conductivity of Korean weathered granite soils using a regression analysis

  • Yoon, Seok;Lee, Seung-Rae;Kim, Yun-Tae;Go, Gyu-Hyun
    • Geomechanics and Engineering
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    • v.9 no.1
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    • pp.101-113
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    • 2015
  • Saturated soil hydraulic conductivity is a very important soil parameter in numerous practical engineering applications, especially rainfall infiltration and slope stability problems. This parameter is difficult to measure since it is very highly sensitive to various soil conditions. There have been many analytical and empirical formulas to predict saturated soil hydraulic conductivity based on experimental data. However, there have been few studies to investigate in-situ hydraulic conductivity of weathered granite soils, which constitute the majority of soil slopes in Korea. This paper introduces an estimation method to derive saturated hydraulic conductivity of Korean weathered granite soils using in-situ experimental data which were obtained from a variety of slope areas of South Korea. A robust regression analysis was performed using different physical soil properties and an empirical solution with an $R^2$ value of 0.9193 was suggested. Besides that this research validated the proposed model by conducting in-situ saturated soil hydraulic conductivity tests in two slope areas.

Shallow Failure Characteristics of Weathered Granite Soil Slope in accordance with the Rainfall Infiltration (강우침투에 따른 화강풍화토 사면의 얕은파괴 특성)

  • Kim, Sun-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2810-2818
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    • 2009
  • In order to examine the characteristic of shallow failure in cut slopes composed of weathered granite soil, this study calculated critical permeability coefficient according to rainfall characteristic in Korea, performed stability analysis according to the representative physical properties of weathered granite soil distributed in Korea such as horizontal distance to the failure surface of cut slope, slope inclination, slope height, and the depth of wetting by rainfall, and analyzed the results. In the results of analyzing critical permeability coefficient, when the local rainfall characteristic was considered, the maximum critical permeability coefficient was $7.16{\times}10^{-4}cm/sec$. We judged that shallow failure according to wetting depth should be considered when rainfall below the critical rainfall intensity lasts longer than the minimum rainfall duration in cut slopes composed of weathered granite soil, which had a critical permeability coefficient lower than the maximum critical permeability coefficient. Furthermore, using simulated failure surface, this study could understand the characteristic of shallow failure in cut slopes based on the change in slope safety factor according to horizontal distance, wetting depth, and strength parameter.