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2026 Vol.42, Issue 4 Preview Page
Evaluation of the Bearing Capacity of Protruded Cast-in-Place Piles for Large-Scale Complex Facilities Based on Field Load Test

대규모 복합 시설에 적용 가능한 돌기 형성 현장타설말뚝에 대한 현장시험 기반의 지지거동 평가

Seokjung Kim1
,
Tae-Young Kwak2
,
Soon-Yong Jeong3
,
Mintaek Yoo4*
김 석중1
,
곽 태영2
,
정 순용3
,
유 민택4*
1Member, Assistant Prof., School of Architecture, Civil and Environmental Engineering, Mokpo National Univ.
2Member, Senior Researcher, Dept. of Geotechnical Engineering Research, Korea Institute of Civil Engineering and Building Technology
3Member, CEO, Easy Geotech
4Member, Assistant Prof., Dept. of Civil Environmental Engineering, Gachon Univ.
1정회원, 국립목포대학교 건축토목환경공학부 조교수
2정회원, 한국건설기술연구원 지반연구본부 수석연구원
3정회원, ㈜이지지오텍 대표이사
4정회원, 가천대학교 토목환경공학과 조교수
*Corresponding Author
31 August 2026. pp. 273-283
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Abstract

A protruded cast-in-place (CIP) pile is constructed by grooving the borehole wall before concreting, thereby forming protrusions along the pile shaft that increase shaft resistance. To quantitatively evaluate this enhanced shaft resistance in pile design, appropriate design equations are required. Accordingly, Korean and international design standards use empirical equations that account for the artificial roughness of the pile shaft. In this study, a CIP pile with protrusions was constructed at a field test site, and its bearing capacity was evaluated using a bidirectional load test. The applicability of the design equations was examined by comparing the bearing capacity evaluated from the load test with that calculated using the design equation. The results showed that the ratio of shaft resistance and base resistance calculated using the U.S. Federal Highway Administration (FHWA) design equations was very similar to those evaluated from the field load test. This agreement supports the applicability of the FHWA design equations for estimating the shaft resistance of CIP piles with artificially formed protrusions. However, additional field load-test data are required to further verify the applicability and reliability of the design equations.

Keywords
Bearing capacity
CIP pile
Load-settlement curve
Protrusion along shaft
Roughness
Shaft resistance

돌기 형성 현장타설말뚝은 일반적인 현장타설말뚝 시공 공정 중 천공-말뚝 타설 사이에 공벽에 홈파기 단계를 추가하여 공벽과 말뚝 주면을 따라 돌기를 형성함으로써 주면 마찰력을 증대시키는 공법이다. 증대된 주면 마찰력에 대한 설계를 정량화 하기 위해서는 설계식이 필요하며, 이를 위해 해외 및 국내 시방서에서는 말뚝 주면에 인공적인 거칠기를 정량화한 경험식을 채택하고 있다. 본 연구에서는 실제 현장에서 돌기 형성 현장타설말뚝을 시공하고 재하시험을 통해 지지력을 평가하고, 그 결과와 설계식으로 산정한 지지력을 비교함으로써 설계식에 대한 적용성을 검토하였다. 그 결과, FHWA의 설계식으로 계산한 주면 마찰력과 선단 지지력의 비율과 재하 시험으로 평가한 비율이 매우 유사하며, 돌기 말뚝의 주면 마찰력 산정시, FHWA의 설계식을 적용할 수 있을 것으로 판단된다. 다만, 향후 추가적인 재하시험 자료를 추가로 확보하여 적용성을 검증할 필요가 있을 것으로 판단된다.

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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 : 42
  • No :4
  • Pages :273-283
  • Received Date : 2026-08-13
  • Revised Date : 2026-08-20
  • Accepted Date : 2026-08-21
  • DOI :https://doi.org/10.7843/kgs.2026.42.4.273
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