All Issue

2013 Vol.29, Issue 12 Preview Page
Compressive Behavior of Micropile According to Pile Spacing and Embedded Pile Angle in Sand

사질토 지반에 설치된 마이크로파일의 설치간격 및 설치각도에 따른 압축거동특성

Doo-Hyun Kyung1
,
Ga-Ram Kim2
,
Dae-Hong Kim3
,
Ju-ho Shin4
,
Jun-Hwan Lee5*
경 두현1
,
김 가람2
,
김 대홍3
,
신 주호4
,
이 준환5*
1Ph.D Candidate, School of Civil and Environmental Engrg., Yonsei Univ.
2Graduate Student, School of Civil and Environmental Engrg., Yonsei Univ.
3Principal Researcher, KEPRI/KEPCO
4KEPRI/KEPCO
5Prof., School of Civil and Environmental Engrg., Yonsei Univ.
1연세대학교토목환경공학과박사과정
2연세대학교토목환경공학과석사과정
3한국전력공사전력연구원책임연구원
4한국전력공사전력연구원연구원
5연세대학교토목관경공학과정교수
*교신저자. *Corresponding Author. 
31 December 2013. pp. 57-67
PDF XML Citation
Abstract

Micropile technology has evolved continuously since its instruction by Fernando Lizzi in the 1950s. The effects of group micropile have been researched by many researchers. The effects of group micropile differ and change with pile length, pile spacing (S), pile angle (θ) and pile embedded conditions. In the present study, the effects of resistance increase and settlement reduction from micropiles were investigated through a series of axial load tests. For the study, axial load tests were performed using mat, group micropiles and micropiled-raft (MPR) in various pile spacing and pile angle conditions. As the result, the effects of resistance of micropiled-raft were 80% (3D) to 110% (7D) of the total resistance of mat and group micropile. The effects of settlement restraint of micropiled-raft were 20% (S=3D, θ=45˚) to 70% (7D,θ=15˚) of settlement of mat foundation.

Keywords
Micropile
Axial load test
Sand
Mat
Group micropile
Micropiled-raft

마이크로파일 기초는 1950년대 Lizzi에 의해 개발된 이후 널리 이용되고 있다. 무리 마이크로파일의 효과에 대한 연구는 많은 연구자들로부터 수행되어 왔다. 무리 형태로 설치된 마이크로파일의 지지성능 발휘 효과는 지반조건 및 말뚝의 길이, 말뚝의 설치 간격(S), 말뚝의 설치각도(θ), 말뚝의 배치조건 등 다양한 변수에 의해 변화된다. 본 연구에서는 다양한 조건에서의 연직재하시험을 통하여 무리 마이크로파일의 저항력증가효과와 침하억제효과를 규명하도록 하였다. 본 연구를 위하여, 전면기초(Mat)와 무리 마이크로파일 기초(GP), 마이크로파일을 이용한 마이크로파일지지 전면기초(MPR)에 대한 연직재하시험을 다양한 설치간격과 설치각도 조건에서 수행하였다. 실험결과 마이크로파일지지 전면기초(MPR)의 저항력이 전면기초(Mat)와 무리 마이크로파일(GP)의 저항력의 80%(S=3D)-110%(S=7D)로 측정되는 것으로 나타났으며, 마이크로파일지지 전면기초(MPR)의 침하억제효과가 전면기초(Mat)의 20%(S=3D, θ=45˚)에서 70%(S=7D, θ=15˚) 수준까지 측정 되는 것으로 나타났다.

References
1
1.ASTM (2006), “Standard test methods for maximum index density and unit weight of soils using a vibratory table”, American Society for Testing and Materials, ASTM D4253-00(2006).
2
2. ASTM (2006), “Standard test methods for minimum index density and unit weight of soils and calculation of relative density”, American Society for Testing and Materals, ASTM D4254-00(2006).
3
3.FHWA (2005), “Micropile Design and Construction Reference Manual”, U.S. Department of Transportation Federal Highway Administration, FHWA NHI-05-039.
4
4.Kim, W.C., Cho, C. H., and Lee, J.H. (2002), “Micropile - Concept and classification of micropile”, Korean Geo-Environmental Society, Technical article : Geo-environmental, Vol.3, No.4, pp.24-79.
5
5.Kim, W.C, Cho, C. H., and Lee, J. H. (2003), “Design of micropile”, Korean Geo-Environmental Society, Technical article : Geo-environmental, Vol.3, No.4, pp.72-79.
6
6.Lee, T. H. and Im, J. C. (2006), “An Experimental Study on the Reinforcement Effect of Installed Micropiles in the Surround of Footing on Dense Sand”, J. of the Korean Geotechnical Society, Vol.22, No.5, pp.69-81.
7
7.Lee, W. T. (1991), “A Study on reinforcing effect of reticulated root piles on shallow footing”, a doctor’s thesis, Seoul National Univ.
8
8.Lizzi, F. and Carnevle, G. (1979), “Les Reseaux de Pieux Racines Pour la Consolidation des sols, Ascepts Theoretique et Essais sur Mondile”, Proc. Int. Conf., Soil Reinforcement, Paris, Vol.2, pp. 317-324.
9
9.O'Neill, M.W. and Hassan, K.M. (1994), “Drilled Shafts: Effects of Construction on Performance and Design Criteria”, Proceedings of the International Conference on Design and Construction of Deep Foundations, December 1994, Vol.1, pp.137-187.
10
10.Turner (1995), “Mike Turner Design Guides for Micropiles”, personal communication.
11
11.Tsukada, Y., Miura, K., Tsubokawa, Y., Otani, Y., and You, G.L. (2006), “Mechanism of bearing capacity of spread footings reinforced with micropiles”, Soils and Foundations, Vol.46, No.3, pp.367-376.
Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 29
  • No :12
  • Pages :57-67
  • Received Date : 2013-08-30
  • Revised Date : 2013-10-25
  • Accepted Date : 2013-12-20
  • DOI :https://doi.org/10.7843/kgs.2013.29.12.57
Journal Informaiton Journal of the Korean Geotechnical Society Journal of the Korean Geotechnical Society
Archives
: Vol.23~28 (2007~2012)
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close