• Title/Summary/Keyword: 소형FWD

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A Study on the Estimation of Relative Compaction on the Subgrade using a Portable FWD (소형 FWD를 이용한 노상토의 다짐도 추정에 관한 연구)

  • Kang, Hee-Bog;Kim, Kyo-Jun;Kang, Jin-Tae;Kim, Jong-Ryeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.6
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    • pp.213-219
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    • 2007
  • This study was intended to estimate of relative compaction on the ground under the load using of portable FWD. The outcome in the wake of the study is highlighted as below. Viewing the variation of dynamic deflection modulus depending on a number of compaction, when a number of compaction increased to 8 (18.3MPa) from 4 (15Mpa), a dynamic deflection modulus increased 27%, and when a number reached to 12 (27.9MPa), it doubled the value indicated in 4. Viewing the relationship between dry density and dynamic deflection modulus in line with the increase in a number of compaction, a number of compaction by the roller reaching to the degree of compaction equivalent to 95% of max dry density was 13, with a dynamic deflection modulus indicating 27MPa ~ 29MPa.

A Study on the Relation between Dynamic Deflection Modulus and In-Situ CBR Using a Portable FWD (소형FWD를 이용한 노상토의 동적변형계수와 현장 CBR의 상관 연구)

  • Kang, Hee Bog;Kim, Kyo Jun;Park, Sung Kyoon;Kim, Jong Ryeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.2
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    • pp.149-155
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    • 2008
  • The road construction, as part of effort to ease the worsening traffic, has been underway throughout the nation, while the existing road has been increasingly losing its load carrying capacity due to such factors as heavy traffic and weathering. In the case of site, the soil type, plasticity index, and specific gravity were SC, 12.2%, and 2.66, respectively. The maximum dry density, optimum moisture content and modified CBR were $1.895g/cm^3$ (Modified Compaction D), 13.6%, and 16.2%, respectively. A correlation of coefficient expressed good interrelationship by 0.90 between the CBR estimated from a dynamic penetration index of dynamic cone penetrometer test and a deformation modulus converted from a dynamic deflection modulus obtained from a portable FWD test.

Evaluation of correlation between Strain mudulus (Ev2) and Deformation modulus (ELFWD) Using Cyclic Plate loading Test and LFWD (소형 FWD와 반복평판재하시험에서의 변형계수(Ev2)와의 상관관계 평가)

  • Choi, Chan-Yong;Lee, Sung Hyok;Bae, Jae Hun;Park, Doo Hee
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.3
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    • pp.33-41
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    • 2011
  • In this study, it conducted a compaction quality control test in 29 domestic construction sites and investigated the relationship between classical method (Cyclic Plate bearing test) and LFWD test with subgrade materials which consist in sandy soil and gravelly soil. According to the test results, the most of soil types were mostly satisfied with specification criterion and gravelly soils were easily satisfied with values over 3 times greater than specification criterion. In term of the correlation relation of soil modulus with the two compaction quality control test methods, it is shown that the sandy soil types were a good correlation, while gravelly soil types with a high stiffness materials were indicated less correlation. After the compensation for stress condition, a linear regression for elastic modulus were higher correlation.