• Title/Summary/Keyword: Soil Analysis

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Simultaneous analysis method of BTEX and TPH in soil (토양중 BTEX와 TPH의 동시분석법에 관한 연구)

  • 신호상;박치후
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.05a
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    • pp.3-8
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    • 2000
  • A simple and rapid simultaneous analysis method of BTEX and TPH in soil was developed. 5g of soil sample were mixed with sodium sulfate and then extracted with 10 mL of mixture of acetone and dichloromethane (1:1). Extraction was performed for 10 min in sonicator and analysis was with GC-FID. The detection limits of BTEX and TPH was 0.8 and 10 mg/kg, respectively. The analytical recoveries were >90% for all BTEX and TPH. Low boiling point fuels and high boiling point fuels are consistently reproduced within RSD 7%. The analysis results show very simple and rapid quantitation of BTEX and TPH in soil sample with low RSD.

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Analysis of soil erosion hazard zone using GIS

  • Kim J. H.;Kim K.T.;Park J. S.;Choi Y.S.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.664-667
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    • 2004
  • This paper is aimed at analyzing the soil erosion hazard zone in farm land. RUSLE was used for an analysis of soil erosion amount, and for the spatial data of basin, soil erosion amount was calculated by extracting the respect topography space related factors of RUSLE using DEM, Landuse, Soil map as base map. As a result of analysis on the calculated soil erosion amount according to land use type, it was analyzed that the most soil erosion occurred in orchard area, i.e., 40.08ton/ha/yr at average. It was classified into 5 classes depending on the calculated soil erosion amount. of which Class V was decided as soil erosion hazard zone, and for this area, 72.5ha or so, $2.4\%$ of the entire farm land was assessed as erosion hazard zone.

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Reinforced Earth Retaining Wall of The Collapsed-A Case Study. (보강토옹벽의 사고사례에 관한 연구)

  • Yoo, Chung-Sik;Jung, Hyuk-Sang;Lee, Soung-Woo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.958-967
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    • 2004
  • This paper deal with cause and analysis about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extracted from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy are cause of the collapse.

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Deflection and buckling of buried flexible pipe-soil system in a spatially variable soil profile

  • Srivastava, Amit;Sivakumar Babu, G.L.
    • Geomechanics and Engineering
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    • v.3 no.3
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    • pp.169-188
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    • 2011
  • Response of buried flexible pipe-soil system is studied, through numerical analysis, with respect to deflection and buckling in a spatially varying soil media. In numerical modeling procedure, soil parameters are modeled as two-dimensional non-Gaussian homogeneous random field using Cholesky decomposition technique. Numerical analysis is performed using random field theory combined with finite difference numerical code FLAC 5.0 (2D). Monte Carlo simulations are performed to obtain the statistics, i.e., mean and variance of deflection and circumferential (buckling) stresses of buried flexible pipe-soil system in a spatially varying soil media. Results are compared and discussed in the light of available analytical solutions as well as conventional numerical procedures in which soil parameters are considered as uniformly constant. The statistical information obtained from Monte Carlo simulations is further utilized for the reliability analysis of buried flexible pipe-soil system with respect to deflection and buckling. The results of the reliability analysis clearly demonstrate the influence of extent of variation and spatial correlation structure of soil parameters on the performance assessment of buried flexible pipe-soil systems, which is not well captured in conventional procedures.

Effect of Input Soil Properties for Round Robin Test on Ground Response Analysis (지반 응답 해석 Round Robin Test의 입력 지반 물성에 따른 지반 응답 특성 영향 고찰)

  • Kim, Bong-Soo;Lee, Sei-Hyun;Choo, Yun-Wook;Park, Sung-Sik;Kim, Dong-Joon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.305-316
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    • 2007
  • Free field ground motion during earthquake is significantly affected by the local soil conditions and it is essential for the seismic design to perform the site specific ground response analysis. So, Round Robin Test (RRT) on ground response analysis was performed for three sites in Korea. A total of 12 teams presented the results of ground response analysis with used input soil properties based on own judgement. In this paper, the results of one dimensional equivalent linear analysis presented by 11 teams were compared to evaluate the effect of input soil properties on ground response analysis. Additionally, 4 influence factors on ground response analysis, that is shear wave velocity of soil layer, nonlinear dynamic deformational characteristics, bedrock depth and bedrock velocity were studied for assumed simple soil conditions.

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Analysis of Soil-Structure Interaction Considering Complicated Soil Profile (복잡한 지층 형상을 고려한 지반-구조물 상호작용 해석)

  • Park, Jang-Ho
    • Journal of the Korean Society of Safety
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    • v.21 no.3 s.75
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    • pp.87-93
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    • 2006
  • When a structure is constructed at the site composed of soil, the behavior of a structure is much affected by the characteristics of soil. Therefore, the effect of soil-structure interaction is an important consideration in the design of a structure at the site composed of soil. Precise analysis of soil-structure interaction requires a proper description of soil profile. However, most of approaches are nearly unpractical for soil exhibiting material discontinuity and complex geometry since those cannot consider precisely complicated soil profiles. To overcome these difficulties, an improved integration method is adopted and enables to integrate easily over an element with material discontinuity. As a result the mesh can be generated rapidly and highly structured, leading to regular and precise stiffness matrix. The influence of soil profile on the response is examined by the presented method. It is seen that the presented method can be easily used on soil-structure interaction problems with complicated soil profile and produce reliable results regardless of material discontinuities.

Spatial Prediction of Soil Carbon Using Terrain Analysis in a Steep Mountainous Area and the Associated Uncertainties (지형분석을 이용한 산지토양 탄소의 분포 예측과 불확실성)

  • Jeong, Gwanyong
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.3
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    • pp.67-78
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    • 2016
  • Soil carbon(C) is an essential property for characterizing soil quality. Understanding spatial patterns of soil C is particularly limited for mountain areas. This study aims to predict the spatial pattern of soil C using terrain analysis in a steep mountainous area. Specifically, model performances and prediction uncertainties were investigated based on the number of resampling repetitions. Further, important predictors for soil C were also identified. Finally, the spatial distribution of uncertainty was analyzed. A total of 91 soil samples were collected via conditioned latin hypercube sampling and a digital soil C map was developed using support vector regression which is one of the powerful machine learning methods. Results showed that there were no distinct differences of model performances depending on the number of repetitions except for 10-fold cross validation. For soil C, elevation and surface curvature were selected as important predictors by recursive feature elimination. Soil C showed higher values in higher elevation and concave slopes. The spatial pattern of soil C might possibly reflect lateral movement of water and materials along the surface configuration of the study area. The higher values of uncertainty in higher elevation and concave slopes might be related to geomorphological characteristics of the research area and the sampling design. This study is believed to provide a better understanding of the relationship between geomorphology and soil C in the mountainous ecosystem.

Applicability Study of Geotextile Mesh Soil Nail on Slope Reinforcement Using Numerical Analysis (수치해석을 이용한 토목섬유망 네일의 사면보강에 대한 적용성 연구)

  • You, Kwang Ho;Jung, Yeun Hak;Ha, Ji Young
    • Tunnel and Underground Space
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    • v.25 no.3
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    • pp.264-274
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    • 2015
  • In this study, the applicability of geotextile mesh soil nails on slopes was evaluated by numerical analysis to reduce environmental problems which a general soil nailing might produce and to improve its economical efficiency and construction convenience. To this end, in situ pull-out tests were conducted for both general soil nail and geotextile mesh soil nail and their pull-out characteristics were analyzed. Also, finite difference method was used to verify the suitability of numerical simulation. Parameters for nail and ground conditions were selected and sensitivity analysis was performed for the evaluation of slope stability. In addition, analysis was performed by limit equilibrium method which is widely used for slope stability analysis in practice. As a result, if the nail diameter was same, there is no big difference between geotextile mesh soil nails and general soil nails in terms of slope stability. Therefore it can be expected that geotextile mesh soil nails could be effective for slope reinforcement since they could keep a slope as stable as general soil nails and give better economical efficiency and construction convenience than general soil nails.

Nonlinear interaction analysis of infilled frame-foundation beam-homogeneous soil system

  • Hora, M.S.
    • Coupled systems mechanics
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    • v.3 no.3
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    • pp.267-289
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    • 2014
  • A proper physical modeling of infilled building frame-foundation beam-soil mass interaction system is needed to predict more realistic and accurate structural behavior under static vertical loading. This is achieved via finite element method considering the superstructure, foundation and soil mass as a single integral compatible structural unit. The physical modelling is achieved via use of finite element method, which requires the use of variety of isoparametric elements with different degrees of freedom. The unbounded domain of the soil mass has been discretized with coupled finite-infinite elements to achieve computational economy. The nonlinearity of soil mass plays an important role in the redistribution of forces in the superstructure. The nonlinear behaviour of the soil mass is modeled using hyperbolic model. The incremental-iterative nonlinear solution algorithm has been adopted for carrying out the nonlinear elastic interaction analysis of a two-bay two-storey infilled building frame. The frame and the infill have been considered to behave in linear elastic manner, whereas the subsoil in nonlinear elastic manner. In this paper, the computational methodology adopted for nonlinear soil-structure interaction analysis of infilled frame-foundation-soil system has been presented.

Daily Changes in Red-Pepper Leaf Surface Temperature with Air and Soil Surface Temperatures

  • Eom, Ki-Cheol;Lee, Byung-Kook;Kim, Young-Sook;Eom, Ho-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.5
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    • pp.345-350
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    • 2014
  • This study was conducted to investigate the changes in daily surface temperature of red pepper leaf compared to air and soil surface temperature. The maximum, minimum and average daily temperatures of red pepper leaf were 27.80, 11.40 and $19.01^{\circ}C$, respectively, which were lower by 0.10, 7.60 and $3.86^{\circ}C$ than air temperature, respectively, and lower by 15.00, 0.0 and $4.38^{\circ}C$ than soil surface temperature, respectively. Mean deviations of the difference between measured and estimated temperature by the E&E Model (Eom & Eom, 2013) for the air and surface temperature of red pepper leaf and soil were 0.64, 1.82 and $4.77^{\circ}C$, respectively. The relationships between measured and estimated scaled factor of the air and surface temperature of red pepper leaf and soil were very close to the 1:1 line. Difference between air and surface temperature of red pepper leaf showed a linear decreasing function with the surface temperature of red pepper leaf. Difference between soil surface temperature and air and surface temperature of red pepper leaf linearly increased with the soil surface temperature.