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2013 Vol.29, Issue 11
A Study on the Ultimate End Bearing Capacity of Drilled Shafts in Rocks

암반에 설치된 현장타설말뚝의 극한선단지지력에 관한 연구

Sangseom Jeong1*
,
Jaehwan Lee2
,
Dohyun Kim3
정 상섬1*
,
이 재환2
,
김 도현3
1Prof., Dept. of Civil Engrg., Yonsei Univ.
2Graduate Strudent, Dept. of Civil Engrg., Yonsei Univ.
3Graduate Strudent, Dept. of Civil Engrg., Yonsei Univ.
1연세대학교 토목공학과 교수
2연세대학교 토목공학과 박사과정
3연세대학교 토목공학과 석사과정
*교신저자. *Corresponding Author. 
30 November 2013. pp. 5-15
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Abstract

The end bearing capacity of rock-socketed drilled shafts under axial loading is investigated by Hoek-cell tests and a numerical analysis. From the test results, it was found that the ultimate end bearing capacity (qmax) was influenced by pile diameter, rock mass modulus and the spacing of discontinuity. A new ultimate end bearing capacity method is proposed by taking end bearing capacity influence factors, including rock mass discontinuity, based on field data. Through comparisons with other field data, the proposed qmax method represents a definite improvement in the prediction of ultimate end bearing capacity of rock-socketed drilled shafts.

Keywords
Ultimate end bearing capacity
Hoek-cell
Numerical analysis (DEM)
Rock discontinuity

본 연구에서는 Hoek-cell을 이용한 실내모형실험 및 개별요소해석을 수행하여 말뚝의 직경, 암반의 강도와 불연속면 조건이 암반에 근입된 현장타설말뚝의 선단부 거동에 미치는 영향을 분석하였다. 이를 통해 영향인자를 선정하였고, 실제 현장재하시험 데이터베이스를 구축하여 암반근입 현장타설말뚝의 극한선단지지력 예측식을 제안하였다. 또한, 제안된 극한선단지지력 산정식을 현장재하시험 결과와 비교･분석하여 그 적용성을 검증하였다. 그 결과, 시험말뚝이 근입된 암반의 불연속면 특성을 고려하지 못하고 일축압축강도만을 이용하여 극한선단지지력을 예측하는 기존 제안식들이 일부 재하시험 결과를 과도하게 예측하는 데 비해, 본 연구의 제안식은 선단부 거동 영향인자를 반영하여, 현장말뚝의 극한선단지지력을 적절히 예측하고 있음을 확인할 수 있었다.

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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 :11
  • Pages :5-15
  • Received Date : 2013-05-09
  • Revised Date : 2013-10-07
  • Accepted Date : 2013-10-10
  • DOI :https://doi.org/10.7843/kgs.2013.29.11.5
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