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2023 Vol.39, Issue 3 Preview Page
Evaluation of the Effect of Waveform Micropiles on Reinforcement of Foundation Structures Through Field Load Tests

현장 재하시험을 통한 파형 마이크로파일의 기초보강 효과 분석

Sung-Ha Baek1
,
Jin-Tae Han2
,
Seok-Jung Kim3
,
Joonyoung Kim4*
백 성하1
,
한 진태2
,
김 석중3
,
김 준영4*
1Member, Assistant Prof., School of Civil and Environmental Engineering & Construction Engineering Research Institute, Hankyong National Univ.
2Member, Research Fellow, Department of Geotechnical Engineering, Korea Institute of Civil Engr. and Building Tech.
3Member, Senior Researcher, Planning and Coordination Department, Korea Institute of Civil Engr. and Building Tech.
4Member, Assistant Prof., Department of Artificial Intelligence, Hannam Univ.
1정회원, 한경국립대학교 건설환경공학부 조교수
2정회원, 한국건설기술연구원 지반연구본부 연구위원
3정회원, 한국건설기술연구원 경영기획실 수석연구원
4정회원, 한남대학교 AI융합학과 조교수
*Corresponding Author
31 March 2023. pp. 29-40
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Abstract

In this study, we investigated the reinforcing effects of waveform micropiles in a stratigraphic setting comprising buried soil, weathered soil, and weathered rock. We conducted a series of field load tests and determined that waveform micropiles exhibited sufficient bearing capacity through frictional resistance in the soil layer and demonstrated favorable constructability in conditions with deep bedrock layers. Moreover, the vertical stiffness of waveform micropiles was approximately 2.2 times higher than that of conventional micropiles when subjected to the same design load. Pile group load tests comprising conventional and waveform micropiles showed that micropiles with higher stiffness carried a greater proportion of the load. Although there was no significant difference in the bearing capacity between conventional and waveform micropiles under the same design load, waveform micropiles with higher stiffness showed a load-carrying capacity 1.7 to 3.2 times greater than that of conventional micropiles. These findings suggest that waveform micropiles can be effectively used for foundation reinforcement and reduce the risk of foundation failure when increased loads due to modifications such as expansion remodeling are expected.

Keywords
Axial load capacity
Axial stiffness
Field load test
Waveform micropile

본 연구에서는 파형 마이크로파일의 기초보강 효과를 분석하기 위해서, 매립토-풍화토-풍화암의 지층구조를 보이는 지반에 마이크로파일을 설치한 뒤 현장 재하시험을 수행했다. 단일 마이크로파일 재하시험 결과, 파형 마이크로파일은 토사층에서 발현되는 주면마찰력만으로도 충분한 지지력을 가져 암반층의 심도가 깊은 지반 조건에서 유리한 시공성을 가질 수 있음을 확인하였다. 또한 동일한 설계하중이 적용되었음에도, 단일 마이크로파일 재하시험 시 설계하중 범위 내에서 평가된 파형 마이크로파일의 연직강성이 일반 마이크로파일의 연직강성에 비해 약 2.2배 큰 것으로 나타났다. 일반 및 파형 마이크로파일로 구성된 무리말뚝 재하시험 결과, 강성이 큰 마이크로파일이 높은 하중을 분담하는 것으로 나타났다. 일반 및 파형 마이크로파일 모두 동일한 설계하중이 적용되어 지지력에는 큰 차이를 보이지 않았음에도, 강성이 큰 파형 마이크로파일이 작게는 1.7배에서 크게는 3.2배 큰 하중 분담율을 보였다. 파형 마이크로파일은 대부분 보강기초로 활용될 것으로 예상되는데, 증축 리모델링 등을 통해 추가적인 하중 작용 시 많은 하중을 분담함으로써 기존 기초의 지지력 파괴 가능성을 낮출 수 있을 것으로 기대된다.

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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 : 39
  • No :3
  • Pages :29-40
  • Received Date : 2023-03-07
  • Revised Date : 2023-03-16
  • Accepted Date : 2023-03-16
  • DOI :https://doi.org/10.7843/kgs.2023.39.3.29
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