• Title/Summary/Keyword: Embankment material

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A Study on Compaction Characteristics of Surplus Soils in Mountainous Areas in Busan, GyungNam Province (부산 경남지역 산지 현장 발생토의 다짐특성 연구)

  • Jung-Uk Kang;Gi-Ju Noh;Tae-Hyung Kim;In-Gon Joo
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.63-70
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    • 2023
  • Most of the industrial complexes and housing complexes in Busan and Gyeongnam were constructed by developing mountainous areas, except for some landfill areas. During the development process, the surplus soil for site development was mainly used as the embankment material. In the field, however, even if the material of the material changes during the embankment work for site development, for convenience reasons such as construction period and site conditions, the material property test and compaction test are not additionally conducted for the embankment material, and quality control is conducted. In this study, physical property tests and compaction tests were conducted on surplus soils in mountainous areas in Busan, GyungNam Province and then regression analysis was performed on the data. In addition, a comparative analysis was conducted along with existing studies in Korea. The surplus soils at the sites in Busan and Gyeongnam were mainly weathered soils of granites, and were classified into clayey sand (SC) and silty sand (SM). As a result of regression analysis of the compaction characteristics according to the content of coarse and fine soils, the correlation between them was very high. Using the relational formula as a result of this study, it will be very useful for compaction management of the surplus soils in the field.

Fracture of rock affected by chemical erosion environment

  • Gao, W.;Ge, M.M.
    • Geomechanics and Engineering
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    • v.11 no.3
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    • pp.373-383
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    • 2016
  • As one natural material, the physical and mechanical properties of rock will be affected very largely by chemical erosion environment. Under chemical environment, the strength of rock will be reduced. Considering the effect of the chemical erosion, fracture factor of rock is reduced. The damage variable is applied to express the change of fracture stress. Therefore, the fracture criterion of rock under chemical environment is constructed. By one experiment of rock fracture under chemical erosion environment, the proposed fracture criterion is verified. The results show that, the fracture path by theory is agree with the testing one well.

Model Test on the Effect of the Depth of Revetment by Inter Sand Layer in Soft Ground (모형토조 실험을 이용한 연약지반내 중간모래층이 호안제방하부 강제치환 깊이에 미치는 영향 연구)

  • Chung, Hyung-Sik;Bang, Chang-Kuk;Lee, Yong-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.956-965
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    • 2005
  • In this paper, the effect on the forced replacement depth of the revetment in soft soil with inter sand layer is analyzed by model test. In the result, the forced replacement occur in 60 second from filling the embankment material. The shape of the forced replacement depth is like to punching shape. Then, in case of thin inter sand layer and near the embankment, the forced replacement depth of inter sand layer case is more than only clayed soil case.

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The Engineering and Environmental Properties for Utilization of Phosphogypsum as Embankment Materials (성토재료로서 인산석고의 공학적.환경적 특성)

  • 이용수;정형식;정하익
    • Journal of the Korean Geotechnical Society
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    • v.17 no.4
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    • pp.331-339
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    • 2001
  • 인산석고(phosphogypsum)는 비료생산과정에서 발생되는 산업부산물로, 주요구성성분은 이수석고(CaSO$_4$.2$H_2O$)의 성분이 대부분이고 여기에 인(P$_2$O$_2$), 철(F)와 유기물질 등으로 이루어져 있다. 전 세계적으로 인산석고 발생량은 현재 1억8천만톤이고 향후 약 3억8천만톤 발생될 것으로 추정되며, 국내에는 약 157만톤이 발생되고 있다. 본 연구는 성토재료로 인산석고를 활용할 경우 이에 대한 물리적 환경적 특성을 분석하였다. 이를 위하여 인산석고와 화강토 혼합비율에 따른 입도분석, 비중시험, 다짐시험, CBR시험, pH시험 및 용출시험 등 일련의 실험을 실시하였다. 실험결과, 인산석고 혼합재료를 성토재료로 활용할 경우 환경적으로 유해한 영향이 적으며, 산업부산물의 자원화 차원에서 대체 성토재료로 활용이 가능한 것으로 나타났다.

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Assessment of Stability of Railway Abutment Using Geosynthetics

  • Kim, Ja-Yeon;Kim, Ji-Hwan;Cho, Kook-Hwan
    • International Journal of Railway
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    • v.9 no.1
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    • pp.15-20
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    • 2016
  • An approach section on an abutment is located between the soil embankment and the structure, which may cause an uneven surface due to different settlement between the abutment and the soil embankment. This study proposes a new type of wall which separates the abutment from the backfill material using mechanically stabilized wall. A new type of keystone which incorporates geotube and wire mesh is proposed and evaluated. Numerical analyses were performed to investigate the applicability of the proposed keystone type, which incorporates Geosynthetic. The maximum horizontal displacements along GRS wall faces, settlements at the top of pavement and track bed, and tensile forces applied on geotextiles under traffic loads were investigated. The results of the numerical analysis showed that the proposed wall can be used for highway and high-speed railway abutment.

An attempt at soil profiling on a river embankment using geophysical data (물리탐사 자료를 이용한 강둑 토양 종단면도 작성)

  • Takahashi, Toru;Yamamoto, Tsuyoshi
    • Geophysics and Geophysical Exploration
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    • v.13 no.1
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    • pp.102-108
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    • 2010
  • The internal structure of a river embankment must be delineated as part of investigations to evaluate its safety. Geophysical methods can be most effective means for that purpose, if they are used together with geotechnical methods such as the cone penetration test (CPT) and drilling. Since the dyke body and subsoil in general consist of material with a wide range of grain size, the properties and stratification of the soil must be accurately estimated to predict the mechanical stability and water infiltration in the river embankment. The strength and water content of the levee soil are also parameters required for such prediction. These parameters are usually estimated from CPT data, drilled core samples and laboratory tests. In this study we attempt to utilise geophysical data to estimate these parameters more effectively for very long river embankments. S-wave velocity and resistivity of the levee soils obtained with geophysical surveys are used to classify the soils. The classification is based on a physical soil model, called the unconsolidated sand model. Using this model, a soil profile along the river embankment is constructed from S-wave velocity and resistivity profiles. The soil profile thus obtained has been verified by geotechnical logs, which proves its usefulness for investigation of a river embankment.

River Embankment Stability against Hydraulic Piping Failure in Korea (우리나라 하천제방에 대한 내부침식 파괴 연구 : 사례연구)

  • Kwon, Kyo-Keun;Han, Sang-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1C
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    • pp.33-42
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    • 2006
  • Lots of river embankments or levees in Korea are quite so old and unknown the origin even. The river deposits, moreover, obtainable easily somewhere were used for materials of embankment without any technical considerations such as the influence soil properties and construction methods on embankment stability. It's natural that safety would be threatened if the water level rises due to flood or rainfall when it comes to abnormal weather conditions, especially. From this point of view, enlargement of embankment, irrigation works, etc. are in progress recently at the situation from a reinforcement work. However, taking influence of soil properties and construction methods on embankment stability into account against cracking or piping is still insufficient. Fragmentary design criteria or irrational construction methods are applied rather as the case may be. In this study, therefore, a way to estimate piping and cracking resistance (Sherard, 1953) has been introduced and reevaluated for practical use with an eye to material properties and its applicability to piping-experienced embankments was examined. Piping possibility was also examined in the present design criteria and compared. In view of the results achieved, it reflects that both yield piping possibility. But it's still necessary to complement how to judge and verify piping resistance of given soils with gradation curves by the representative curve, quantitatively and that piping resistance should consider compaction effects as well.

Decision Making Model for Optimal Earthwork Allocation Planning (최적 토량배분 계획을 위한 의사결정 모델)

  • Gwak, Han-Seong;Seo, Byoung-Wook;Lee, Dong-Eun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.162-163
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    • 2016
  • This paper presents a mathematical model for optimizing earthwork allocation plan that minimizes earthwork cost. The model takes into account operational constraints in the real-world earthwork such as material-type (i.e., quality level of material) and quantities excavated from cut-sections, required quality of material and quantities for each embankment layer, top-down cutting and bottom-up filling constraints, and allocation orders. These constraints are successfully handled by assuming the rock-earth material as the three dimensional (3D) blocks. The study is of value to project scheduler because the model identifies the optimal earth allocation plan (i.e., haul direction (cut and fill pairs), quantities of soil, type of material, and order of allocations) expeditiously and is developed as an automated system for usability. It is also relevant to estimator in that it computes more realistic earthworks costs estimation. The economic impact and validity of the mathematical model was confirmed by performing test cases.

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Effects of bed material on scouring under high-velocity flow conditions (고유속 흐름에서 하상재료에 따른 세굴 영향 연구)

  • Kim, Gwang Soo;Jung, Dong Gyu;Kim, Young Do;Park, Yong Sung
    • Journal of Korea Water Resources Association
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    • v.52 no.2
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    • pp.133-139
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    • 2019
  • In this study, the degree of scouring according to the bed material according to the flow rate and the relationship between the flow velocity and the bed scouring were investigated in order to examine the operability of the revetment and embankment. The materials used in the experiment were sand and loess as materials used in the embankment. We measured the scouring of the material according to the change of the flow velocity by using the indoor high flow velocity experiment device and verified the flow rate. In this way, The purpose of this study was to compare and analyze changes in material before and after scouring, and compare basal scouring evaluation by bed material with high flow velocity. In case of sand, the cohesive force is very weak, so more than 40% of the material is lost even at less than 1.0 m/s. In the case of loess, less than 6% of the bed material is lost at more than 2 m/s. The reason why the material was lost was that the cohesion was so strong that the material was dried after the compaction and cracked. As a result, the material was lost from the part where the dry crack occurred. In this study, the composition and loss of bed materials were evaluated.

Numerical Analysis on Pore Water Pressure Reduction at Embankment Foundation of Fill Dam and Levee by Relief Well (감압정에 의한 필 댐 및 제방 기초지반의 간극수압 저감효과 수치해석)

  • Chang, Jaehoon;Yoo, Chanho;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.2
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    • pp.25-36
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    • 2022
  • In this study, seepage control effect of relief well was evaluated quantitatively on embankment of small fill dam and levee. Seepage analysis of dam and levee were carried out according to the permeability of fill material and foundation and to analyze behaviour characteristics of seepage. The up-lift pressure at toe of embankment was analyzed which is generated by seepage according to relief well installation condition. The relief well could reduce pore water pressure which is to cause piping or up-lift pressure at foundation ground of embankment and it does not be influenced on geometric condition such as dam height and slope incline. In case of relative low permeable ground, the pore water pressure reduction effect of relief well was decreased compare with high permeable ground but it shows pore water pressure reduction effect compare with no relief well condition. The reduction effect of relief well shows relative gap according to diameter and penetration length of relief well and the installation length of relief well is the most effective factor for seepage control.