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Research Article

A Study on the Confined Effects of Highly Moistured Soils Reinforced with Geosynthetics

토목섬유가 보강된 고함수비 흙의 구속효과에 관한 연구

Jae-Won Yoo1
,
Jong-Chul Im2*
,
Sang-Kyun Kang3
,
Hyung-Jun Lee4
,
Moon-Bong Choi5
유 재원1
,
임 종철2*
,
강 상균3
,
이 형준4
,
최 문봉5
1Member, Research Professor, Research Institute of Industrial Technology, Pusan National Univ.
2Member, Professor, Department of Civil and Environmental Engineering, Pusan National Univ.
3Member, Director, Korea Port Engineering Corporation
4Nonmember, Graduate Student, Department of Civil and Environmental Engineering, Pusan National Univ.
5Nonmember, Graduate Student, Department of Civil and Environmental Engineering, Pusan National Univ.
* Corresponding Author
30 March 2019. pp. 25-37
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Abstract

본 연구에서는 고함수비 상태의 흙의 토목섬유 보강에 의한 다짐효과를 확인하고자 실내다짐실험, 현장다짐실험, 수치해석을 실시하였다. 토목섬유의 구속효과를 검증하기 위해 D다짐실험의 몰드(래머/몰드의 면적비=0.33) 보다 큰 몰드(래머/몰드의 면적비=0.19)를 이용하여 다짐을 실시한 결과, D다짐실험에서는 고함수비 구간의 건조밀도가 0.5∼0.6% 증가하였지만, 큰 몰드를 이용한 다짐실험에서는 2.4∼3.7%가 증가하는 것으로 분석되어 하중 작용면에 비해 측면지반의 면적이 충분히 넓을 경우, 함수비가 높은 구간에서도 토목섬유 보강에 의한 구속효과가 발생하였다. 현장다짐실험에서 ‘전압면으로부터의 심도(z/B)’에 따른 고함수비 구간 흙의 다짐효과를 분석한 결과, 무보강 시에는 과도전압으로 인해 다짐상태가 나빠져 다짐이 잘 되지 않았지만, 토목섬유를 보강할 경우 구속효과의 발생으로 다짐층에 다짐에너지가 효과적으로 전달되고 건조밀도가 증가함을 확인하였다. 또한, 토목섬유와 토사층의 거동에 대한 개념적 모델을 통하여 토목섬유의 보강으로 인한 지반내 매커니즘을 설명하였고, 이를 유한요소해석을 통해 검증하였다.

This study confirms reinforcing effect of geosynthetics in the use of soil at higher water contents as a compaction material on compaction tests, field compaction tests, and numerical analysis. To verify a confined effect, a large mold(area ratio of rammer / mold = 0.19) larger than D compaction mold(area ratio of rammer / mold = 0.33) was performed for compaction. It showed that in the D compaction test, dry density were 0.5∼0.6% increases and in the compaction test using the large mold, it were 2.4∼3.7% increases at high water contents. It shows that when the area of compacted area is large enough, a confined effect could be arising from the reinforcement of geosynthetics even at high water contents. As a result of analyzing of compaction effects according to ‘depth(z/B) from compacted surface’ in the field, when not reinforced, the compaction state deteriorated due to the over-compaction and the compaction did not work well. However, when reinforcement of geosynthetics, restraint effect by geosynthetics occurs, it is confirmed that the compaction energy is effectively transferred to the compaction layer and the dry density is increased. Also, through the conceptual model of the behavior of geosynthetic and soil layer, the mechanism in the ground due to reinforcement of geosynthetics is presented and it is verified through finite element analysis.

Keywords
Geosynthetic
Reinforcement
High water contents
Confined effect
Compaction test

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Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 18
  • No :1
  • Pages :25-37
  • Received Date : 2019-01-16
  • Revised Date : 2019-02-28
  • Accepted Date : 2019-03-13
  • DOI :https://doi.org/10.12814/jkgss.2019.18.1.025
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