• Title/Summary/Keyword: 암거

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Desalinization Effect of Subsurface Drainage System with Rice Hull Packing (왕겨충전에 따른 암거의 제염 효과)

  • Lee, Seung-Heon;An, Yeoul;Yoo, Sun-Ho;Jung, Yeong-Sang
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.5
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    • pp.63-69
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    • 2001
  • The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

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Compaction Induced Lateral Earth Pressures (뒷채움의 다짐에 의한 횡방향(橫方向) 토압(土壓))

  • Chung, Sung Gyo;Chung, In Joon;Kim, Myoung Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.2
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    • pp.51-64
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    • 1991
  • To evaluate the compaction - induced lateral earth pressure acting on retaining structures such as retaining walls, abutments, culverts, underground walls, etc., a new equation is developed using the newly proposed hysteretic model simulating soil's loading - unloading behavoir under Ko-condition. The lateral pressurds calculated by the new equation are found to agree well with those of field tests previously performed by other researchers.

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Application Methodologies of Post-Tensioned Concrete Pavements for Specialized Section Pavements (특수 구간 도로 포장에 포스트텐션 콘크리트 포장 적용 방안)

  • Bae, Jong-Oh;Park, Hee-Beom;Kim, Seong-Min
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.167-174
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    • 2011
  • This research was conducted to propose the design methodologies of post-tensioned concrete pavements (PTCPs) for specialized section pavements. The specialized sections considered in this study included bus stop sections in urban bus-only lanes and culvert existing highway sections that often showed severe failures. The PTCP designs of those specialized sections were performed based on both the stresses and the fatigue failures, and more conservative design results were selected. In the stress based design, the maximum tensile stress under extreme load conditions was obtained using finite element analyses first. Then, the number of tendons and the tendon spacing were determined so that the tensile stress was less than the allowable flexural strength. The AASHTO fatigue failure equations were used in the fatigue failure based design. From this study, the design methodologies of PTCP for bus stop sections in bus-only lanes and culvert existing highway sections were successfully suggested.