• Title/Summary/Keyword: Soil problems

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Structural and Fatigue Analysis for soil-Cement Stabilized Base and Subbase of Road (Soil-cement 안정처리 도로 기층 및 보조기층의 구조 및 피로해석)

  • 도덕현;조래청
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.10a
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    • pp.43-50
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    • 1993
  • It has been past for many years that soil-cement used in the field of roadway pavement in America and Europe. Though the design and construction criteria on soil-cement pavement have been well setablished in Korea's specificaions, this method has not been applied in roadway pavements, in practices. It is mainly caused by the lacks of experiences in soil-cement pavement design and construction. In this study, the problems of soil-cement pavement in use were explored, and the structure and fatigue like of soil-cement bases and subbases were estimated.

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Lime addition chemical stabilization of expansive soil at Al-Kawamil city, Sohag region, Egypt

  • Farghaly, Ahmed Abdelraheem;El-Shater, A.;Naiem, Mostafa Abdou Abdel;Hamdy, Fatma
    • Advances in Computational Design
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    • v.5 no.1
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    • pp.1-11
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    • 2020
  • Soil is the fundamental element in the construction process. Soil problems affect the safety of the structures, even so the high quality of the structures and so, bad soil found the structures will affect the lifetime or even destroy the structures built on it. Therefore, the study of soil is an important step in the construction process and the investigation of the most effective characteristics of a special kind of soil (shale soil), i.e. Atterberg limits, swelling pressure, swelling potential and unconfined compression strength, are the most effective soil properties. A big projects will be constructed in new urban extension areas with expansive shale soils, like at Al-Kawamil and new Akhmim shale soils which associated with soil problems, treatment system should be used to ensure the stability of the soil under the structures foundations one of the most effective methods is by adding lime solution to the soil by specific quantities, which affect on the properties of the shale soil by decreasing the swelling and increasing the compressive strength of the treatment soils. Experimenting with the soil added to the lime, it was found that the addition of lime solution 6% improve c j the properties of the soil. The results of the tests showed the high effectiveness of using lime in the treatment of Al-Kawamil soil

Comparison of soil erosion simulation between empirical and physics-based models

  • Yeon, Min Ho;Kim, Seong Won;Jung, Sung Ho;Lee, Gi Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.172-172
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    • 2020
  • In recent years, soil erosion has come to be regarded as an essential environmental problem in human life. Soil erosion causes various on- and off-site problems such as ecosystem destruction, decreased agricultural productivity, increased riverbed deposition, and deterioration of water quality in streams. To solve these problems caused by soil erosion, it is necessary to quantify where, when, how much soil erosion occurs. Empirical erosion models such as the Universal Soil Loss Equation (USLE) family models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well by utilizing big data related to climate, geography, geology, land use, etc. within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models remain powerful tools to distinguish erosion-prone areas at the macro scale but physics-based models are necessary to better analyze soil erosion and deposition and eroded particle transport. In this study, the physics-based Surface Soil Erosion Model (SSEM) was upgraded based on field survey information to produce sediment yield at the watershed scale. The modified model (hereafter MoSE) adopted new algorithms on rainfall kinematic energy and surface flow transport capacity to simulate soil erosion more reliably. For model validation, we applied the model to the Doam dam watershed in Gangwon-do and compared the simulation results with the USLE outputs. The results showed that the revised physics-based soil erosion model provided more improved and reliable simulation results than the USLE in terms of the spatial distribution of soil erosion and deposition.

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Policy of Soil Environment and Restoration Technology-Status and Recent Changes (토양환경 정책 및 복원 기술-현황과 최근변화)

  • Jang, Yeon-Su
    • Journal of the Korean Professional Engineers Association
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    • v.41 no.3
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    • pp.30-34
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    • 2008
  • Recently problems of soil and groundwater contamination occur in major construction sites of highway, dam and railways. Contaminants of oil fuels are also detected in the former fuel storage facilities of railroad station and army troops of transportation, etc. These facilities are planned as the sites of commercial infrastructures after restoration from pollutants by the law of soil environment conservation of Korea. In this manuscript, the contents of soil environment conservation law including soil assessment and restoration technology are introduced. Recent changes of soil environment area are also analyzed.

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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.

The Development of Corrosion Standard System of Water and Wastewater in Soil Environment (상·하수도 배관재의 토양환경에서의 부식표준시스템 개발)

  • Park, Kyeong-Dong;Shin, Yeong-Jin;Lee, Ju-Yeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.4
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    • pp.7-12
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    • 2006
  • Galvanized steel pipe, copper pipe and stainless steel pipe, which is being used in waterworks piping materials. In case of galvanized steel pipe, the precipitation of a product is being generated due to the pollution of the tap water, a white water phenomenon, and various corrosion reaction because a zinc ion is melted by tap water. And in case of a cupper pipe, many problems which is harm in sanitation appeared because of a inflow of harmfulness substance by a frequent accident of a water leakage. So, to prevent these problems, it is substituted for stainless steel pipe. However, those problems is still occurring because of badness of welding, a problem of a water leakage in connection part, and a increment of construction expenses. Therefore, this research has examined the laying period according to each piping thickness and a corrosion shape according to each laying depth after laying in various soils(sandy loam, loamy, clay loam, clay) using galvanized steel pipe, copper pipe, and stainless steel pipe. That is, we has studied the data which is necessary for a rational method of preserving the quality of water by examining the corrosion properties of piping materials in the soil environment which waterworks piping materials is being used.

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MANACING SALINITY PROBLEMS IN RICE FIELDS

  • Sanil, K.;Daham, M.D.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.556-564
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    • 1993
  • The response of salt affected rice soils to salinity reclaimation by flushings and chemical amelioration by lime and gypsum were evaluated . Soils with good drainage system responded well to simple reclimation . The effects of seawater intrusion were reduced efficiently in a very short time. Yields of rice crops recovered to their potential level within one to two seasons of cropping. Soil profile strength was also improved under well drained areas. However, when drainage system was ineffective the problems of salinity and soil strength remained unsolved. Under both condition, water depth management played important role in the survival of rice crop under the sline soil conditions.

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Implementation of Coupled Hydro-Mechanical Problems in Partially Saturated Soils (불포화 지반에 물의 침투와 흙의 변형이 사면의 안정성에 미치는 영향)

  • Kim, Jaehong;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.5
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    • pp.35-43
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    • 2010
  • Partially saturated permeability should be defined by the function of suction (or degree of saturation) and porosity. However, commercial software and most researchers' model often describe as the function of suction. The stability of a soil slope can be affected by both hydraulic and shear strength properties of partially saturated soils. For both studies, we generally use an uncoupled seepage analysis program Seep/W(Geo-Slope, 2007) and a series stress-deformation analysis program Sigma/W, or slope stability analysis program Slope/W. Seep/W is performed for simulations of partially saturated flow problems in non-deformable soil media. However, under real situations, the water flow processes in a deformable soil are influenced by soil skeleton movement and the pore water pressure changed due to seepage will lead to changes in stresses and to deformation of a soil. Many researchers are currently developing their models for solving coupled hydro-mechanical problems to simulate slope stability during a rainstorm. For a proper implementation in the field, the developed model should be still needed in order to achieve appropriate accuracy of the solution for coupled hydro-mechanical problems in soil slope stability. Thus, the paper presents the comparison of slope stability between uncoupled and coupled analyses of seepage and stress deformation problems.

The Study on the Evaluation of Environment Function at Small Stream - In the Case of Hongdong Stream in Hongsung-gun - (농촌지역 소하천의 환경성 평가 연구 - 홍성군 홍동천을 사례로 -)

  • Kang, Banghun;Son, Jin-Kwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.5
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    • pp.81-101
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    • 2011
  • This study was conducted to understand the environmental and ecological function of habitat through evaluation of water environment, soil environment, vegetation characteristics, macro-invertebrate characteristics, and visual habits environment evaluation (SVAP) in Hongdong stream located in Hongseong-Gun, Chungnam Province, and hereafter to utilize the results for the habits reconstruction and improvement project. As the results of water quality analysis, BOD, COD, T-P was almost below the standard quality from upper stream to down stream. The construction of small reservoir, wetland and water purification facility, and the management of non-point pollution are proposed to improve these problems. The soil texture was sandy soil, which is unfitted with vegetation development. The construction of shallows and bogs, and induction of soil sedimentation and biotope formation are proposed to improve these problems. In the plant flora, total 90 kinds were observed with 81 species and nine varieties in total 36 families and 85 genera, and the naturalization rate was higher at down area than upper area. As the results of macro-invertebrate fauna survey, total 26 species and 297 individuals in 20 families and 22 genera were collected. Peltodytes sinensis, Chironomidae sp., and Culicidae sp., which are observed at polluted environment, were collected as dominant species. An appropriate vegetation management party idea is necessary, and it is done an idea in consideration of the soil and a physical characteristic. Visual habits environment evaluation (SVAP) result was mostly determined with below normal (Fair) grade. Pollution source interception, purification pond establishment, and various bog establishment are proposed to improve these problems. With the above results, the ecological environment was determined with bad condition, and the improvement of biotope was urgently needed through sustainable monitoring and management of streams habitat in rural area.