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A Study on Settlement and Load Distribution Behavior of Piled Raft Foundations Due to Groundwater Fluctuations Using Centrifuge Tests

원심모형 실험을 이용한 지하수위 변동에 따른 사질토 지반에 설치된 말뚝지지 전면기초의 침하 및 하중 분담 거동에 관한 연구

Ji-Yeong Lee1
,
Dong-Gun Nam2
,
Jong-Hyeog Yoon3
,
Aizhan Sagu4
,
Myeong-Bin Kim3
,
Min-Wook Kim3
,
Jun-Hwan Lee5*
이 지영1
,
남 동건2
,
윤 종혁3
,
Aizhan Sagu4
,
김 명빈3
,
김 민욱3
,
이 준환5*
1Member, Postdoctoral Researcher, Dept. of Civil and Environmental Engineering, Yonsei Univ.
2Member, Graduated Student, Dept. of Civil and Environmental Engineering, Yonsei Univ.
3Graduated Student, Dept. of Civil and Environmental Engineering, Yonsei Univ.
4Graduated Student, Dept. of Civil and Environmental Engineering, Yonsei Univ.
5Member, Prof., Dept. of Civil and Environmental Engineering, Yonsei Univ.
1정회원, 연세대학교 건설환경공학과 박사후연구원
2정회원, 연세대학교 박사과정
3비회원, 연세대학교 박사과정
4비회원, 연세대학교 석사과정
5정회원, 연세대학교 건설환경공학과 교수
*Corresponding Author
28 February 2026. pp. 19-26
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Abstract

In this study, centrifuge tests were conducted to investigate the influence of fluctuating groundwater levels (GWLs) on the behavior of piled raft foundations in sandy soil. To replicate the in situ stress conditions, the tests were performed under a centrifugal acceleration of 50g. The settlement (spr) and load-sharing ratio (αp) of the foundation were quantitatively analyzed during GWL successive rising and falling phases. The results revealed that as the GWL rose, the soil effective stress decreased and the matric suction in the unsaturated zone dissipated. This led to a considerable reduction in the shaft resistance and end-bearing capacity of the piles, triggering a “forced load redistribution” such that the superstructure load was transferred to the raft. The αp, which was initially 0.69, decreased drastically to 0.38 as the GWL approached the ground surface. Notably, irreversible hysteresis was observed; even when the GWL fell and the effective stress recovered, the load-sharing ratio remained constant owing to the residual contact pressure beneath the raft. Over three cycles of GWL fluctuation, cumulative settlement was the highest during the first cycle; with the behavior gradually converging to a steady state in subsequent cycles. These findings emphasize that piled raft foundations designed for areas with frequent GWL fluctuations must account for increased load demand on the raft and the potential for accumulated settlement during GWL rising phases.

Keywords
Centrifuge test
Groundwater
Load sharing ratio
Piled raft
Settlement

본 연구에서는 기후 변화 등으로 인한 지하수위(GWL) 변동이 사질토 지반에 설치된 말뚝지지 전면기초(Piled Raft Foundation)의 거동에 미치는 영향을 규명하기 위해 원심모형실험(centrifuge test)을 수행하였다. 실제 현장 응력 상태를 모사하기 위해 50g의 원심가속도 조건에서 실험을 진행하였으며, 지하수위의 상승 및 하강 주기에 따른 기초의 침하량(spr)과 하중 분담률(αp)의 변화를 정량적으로 분석하였다. 실험 결과, 지하수위가 상승함에 따라 지반의 유효응력 감소 및 불포화 영역의 흡입력(suction) 손실로 인해 말뚝의 주면마찰력과 선단지지력이 약화되었으며, 이로 인해 상부 하중이 전면기초로 전이되는 ‘강제적 하중 재분배’ 현상이 관찰되었다. 초기 약 0.69였던 αp는 지하수위가 지표면 부근까지 상승함에 따라 0.38까지 급격히 감소하였다. 특히, 수위가 하강하여 유효응력이 회복되더라도 이미 발생한 침하와 전면기초 하단의 접지압 고착화로 인해 하중 분담률이 회복되지 않는 비가역적인 이력 현상(hysteresis)이 확인되었다. 3회의 반복적인 수위 변동 결과, 첫 번째 주기에서 누적 침하의 상당 부분이 발생하였으며 주기가 반복될수록 거동이 특정 임계치로 수렴하는 양상을 보였다. 본 연구 결과는 지하수위 변동이 빈번한 지역의 말뚝지지 전면기초 설계 시, 수위 상승에 따른 전면기초의 분담 하중 증가와 누적 침하를 반드시 고려해야 함을 시사한다.

References
1

Bob, M., Rahman, N., Elamin, A., and Taher, S. (2016), “Rising Groundwater Levels Problem in Urban Areas: A Case Study from the Central Area of Madinah City, Saudi Arabia”, Arabian Journal for Science and Engineering, Vol.41, pp.1461-1472, https://doi.org/10.1007/s13369-015-1976-3.

10.1007/s13369-015-1976-3
2

Choi, K. J., Park, D. G., and Lee, J. H. (2012), “Load Sharing Analysis of Piled Rafts based on Non-linear Load-settlement Characteristics”, Journal of the Korean Geotechnical Society, Vol.28, No.11, pp.30-40, https://doi.org/10.7843/kgs.2012.28.11.33. (in Korean)

10.7843/kgs.2012.28.11.33
3

Clancy, P. and Randolph, M. F. (1996), “Simple Design Tools for Piled Raft Foundations”, Geotechnique, Vol.46, No.20, pp.313-328, https://doi.org/10.1680/geot.1996.46.2.313.

10.1680/geot.1996.46.2.313
4

Gattinoni, P. and Scesi, L. (2017), “The Groundwater Rise in the Urban Area of Milan (Italy) and its Interactions with Underground Structures and Infrastructures”, Tunnelling and Underground Space Technology, Vol.62, pp.103-114, https://doi.org/10.1016/j.tust.2016.12.001.

10.1016/j.tust.2016.12.001
5

Jeong, S., Lee, J., Park, J., Roh, Y., and Hong, M. (2017), “Analysis of Load Sharing Ratio of Piled Raft Foundation by Field Measurement”, Journal of the Korean Geotechnical Society, Vol.33, No.8, pp.41-52, https://doi.org/10.7843/kgs.2017.33.8.41. (in Korean)

10.7843/kgs.2017.33.8.41
6

Ketcham, S. A. and Black, P. B. (1995), “Initial Results from Small-scale Frost Heave Experiments in a Centrifuge.” (No. CRREL959)

7

Kim, H., Oh, T. M., Kim, M. K., Lee, J. W., and Baek, Y. (2018), “Case Study on the Foundation Design of Super High-rise Buildings”, Journal of the Korean Society of Hazard Mitigation, Vol.18, No.2, pp.317-327, https://doi.org/10.9798/KOSHAM.2018.18.2.317.

10.9798/KOSHAM.2018.18.2.317
8

Lee, J., Park, D., and Choi, K. (2014), “Analysis of Load Sharing behavior for Piled Rafts Using Normalized Load Response Model”, Computers and Geotechnics, Vol.57, pp.65-74, https://doi.org/10.1016/j.compgeo.2014.01.003.

10.1016/j.compgeo.2014.01.003
9

Lee, J., Park, D., Park, D., and Park, K. (2015), “Estimation of Load-sharing Ratios for Piled Rafts in Sands that Includes Interaction Effects”, Computers and Geotechnics, Vol.63, pp.306-314, https://doi.org/10.1016/j.compgeo.2014.10.014.

10.1016/j.compgeo.2014.10.014
10

Meyerhof, G. G. (1963), “Some Recent Research on the Bearing Capacity of Foundations”, Can Geotech J, 527 1(1):16-26, https://doi.org/10.1139/t63-003.

10.1139/t63-003
11

Meyerhof, G. G. (1976), “Bearing Capacity and Settlement of Pile Foundations”, J Geotech Eng Div, 529 102(3):197-228, https://doi.org/10.1061/AJGEB6.0000243.

10.1061/AJGEB6.0000243
12

Roh, Y., Kim, I., Kim, G., and Lee, J. (2019), “Comparative Analysis of Axial Load Capacity for Piled-raft Foundation with Changes in Groundwater Level”, KSCE Journal of Civil Engineering, Vol.23, No.10, pp.4250-4258, https://doi.org/10.1007/s12205-019-0239-3.

10.1007/s12205-019-0239-3
13

Song, J. W. (2003), A Study on Load Bearing Capacity of Piled Raft Using Finite Element Analysis, Master’s Dissertation, Sunmoon University (in Korean).

14

You, K. and Jung, Y. (2016), “A Parametric Study to Estimate the Behavior of a Piled Raft Foundation Influenced by ground Conditions”, Journal of the Korean Geotechnical Society, Vol.32, No.8, pp.35-46, https://dx.doi.org/10.7843/kgs.2016.32.8.35. (in Korean)

10.7843/kgs.2016.32.8.35
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 :1
  • Pages :19-26
  • Received Date : 2026-11-17
  • Revised Date : 2026-02-24
  • Accepted Date : 2026-02-24
  • DOI :https://doi.org/10.7843/kgs.2026.42.1.19
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