All Issue

2026 Vol.25, Issue 3 Preview Page

Research Article

Probabilistic Stability Assessment and Fragility Curve Development for Multiple River Embankment Cross-Sections under Water-Level Fluctuations

수위 변동에 따른 국내 하천 제방 다수 단면의 확률론적 안정성 평가 및 취약도 곡선 작성

Jong-Won Lee1
,
Jin-Tae Han2
,
Duhan Lee3
,
Seokjung Kim4
,
Dong-Chan Kim5
,
Sung-Eun Cho6*
이 종원1
,
한 진태2
,
이 두한3
,
김 석중4
,
김 동찬5
,
조 성은6*
1Mamber, Graduate Student, KICT School, University of Science and Technology, 283 Goyang-daero,Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 10223, Republic of Korea
2Member, Senior Research Fellow, Korea Institute of Civil Engineering. and Building Technology, KICT, 283 Goyang-daero, Ilsanseo-gu, Goyang-si, Gyeonggi-do 10223, Republic of Korea
3Non-Member, Senior Research Fellow, Korea Institute of Civil Engineering. and Building Technology, KICT, 283 Goyang-daero, Ilsanseo-gu, Goyang-si, Gyeonggi-do 10223, Republic of Korea
4Non-member, Assistant Professor, School of Architectural, Civil and Environmental Engineering, Mokpo National University, 1666 Yeongsan-ro, Cheonggye-myeon, Muan-gun, Jeollanam-do 58554, Republic of Korea
5Member, Senior Researcher, Green Energy Institute, 177 Samhyangcheon-ro, Mokpo-si, Jeonnam-Gwangju 58656, Republic of Korea
6Mamber, Professor, School of Civil and Environmental Engineering & Construction Engineering Research Institute, Hankyong National Univ., 327 Jungang-ro, Anseong-si, Gyeonggi-do 17579, Republic of Korea
*Corresponding Author
30 September 2026. pp. 31-48
PDF XML Citation
Abstract

This study evaluated the time-dependent stability and relative fragility of 24 cross-sections obtained from investigation data for a river embankment along the ○○ River in Korea under water-level fluctuations. Using Slide2, transient seepage analysis was performed based on the finite element method to determine the time-dependent pore-water pressure distributions. The results were then coupled with limit equilibrium analyses to conduct deterministic and probabilistic slope stability assessments. Cohesion and friction angle were modeled as independent lognormally distributed random variables, and a response surface based on polynomial chaos expansion (PCE) was employed to improve computational efficiency. To screen representative vulnerable sections, 50,000 Monte Carlo simulations (MCS) were conducted at each time step for all 24 cross-sections. CS-01 and CS-22, which exhibited maximum probabilities of failure of 40.1% and 60.5%, respectively, were selected as the representative vulnerable sections. Rather than directly comparing the failure probabilities of the two sections, their time-dependent stability and fragility were evaluated separately by varying the initial water level, H, under the water-level conditions assigned to each section. For each initial water-level condition, 100,000 MCS were conducted at every time step, and fragility curves were developed to represent the relationship between the initial water level and the maximum probability of failure during the corresponding water-level history. The maximum probability of failure increased to 71.9% for CS-01 and 86.9% for CS-22. The critical conditions of the two cross-sections occurred either during the transient rapid-drawdown stage, when the stabilizing effect of external water pressure decreased rapidly while the dissipation of pore-water pressure within the embankment was delayed, or at the end of the drawdown. The developed fragility curves can support the relative screening of multiple embankment cross-sections under a consistent dataset and analytical framework and may assist in prioritizing detailed investigations and reinforcement measures.

Keywords
River embankment
Water-level fluctuation
Slope stability
Monte Carlo Simulation
Transient seepage
Fragility curve

본 연구에서는 국내 ○○천 제방 조사자료에 근거한 24개 단면을 대상으로 수위 변동에 따른 시간의존적 안정성과 상대적 취약성을 평가하였다. Slide2를 사용하여 유한요소법에 의한 비정상 침투해석을 수행하고 시간별 간극수압 분포를 산정한 후, 그 결과를 연계하여 한계평형법 기반의 결정론적 및 확률론적 사면안정해석을 수행하였다. 점착력과 내부마찰각은 서로 독립인 대수정규 확률변수로 고려하였으며, 계산 효율을 높이기 위해 다항식 카오스 전개(PCE) 기반 응답면을 적용하였다. 대표 취약 단면 선별을 위해 24개 단면의 각 시간 단계에서 50,000회의 몬테카를로 시뮬레이션(MCS)을 수행하였으며, 최대 파괴확률이 각각 40.1%와 60.5%로 나타난 CS-01과 CS-22를 대표 취약 단면으로 선정하였다. 이후 두 단면의 파괴확률을 직접 비교하기보다, 각 단면에 적용된 수위 조건에서 초기수위 H의 변화에 따른 시간의존적 안정성과 취약성을 개별적으로 분석하였다. 각 초기수위 조건의 시간 단계마다 100,000회의 MCS를 수행하고, 초기수위와 수위 이력 중 최대 파괴확률의 관계를 나타내는 취약도 곡선을 작성하였다. 해석 결과, 최대 파괴확률은 CS-01에서 71.9%, CS-22에서 86.9%까지 증가하였다. 두 단면의 임계상태는 외부수압의 지지효과가 빠르게 감소하는 반면 제체 내부 간극수압의 소산은 지연되는 수위 급강하 과정의 과도상태 또는 수위 급강하 종료 시점에서 발생하였다. 본 연구에서 작성한 취약도 곡선은 동일한 자료와 해석체계에서 다수 제방 단면의 상대적 취약성을 선별하고, 정밀조사 및 보강 우선순위를 결정하는 데 활용될 수 있다.

References
1

Ahn, K. H. (2009), Combined Reliability Model for Levee Embankment Integrated Stochastic Characterization of Rainfall Variation, Doctoral Thesis, Kyungpook National University (in Korean).

2

Alonso, E. E. and Pinyol, N. M. (2016), “Numerical analysis of rapid drawdown: Applications in real cases”, Water Science and Engineering, Vol.9, No.3, pp.175-182.

10.1016/j.wse.2016.11.003
3

Cho, S. E. (2021), “Probabilistic assessment of seepage stability of soil foundation under water retaining structures by fragility curves”, Journal of the Korean Geotechnical Society, Vol.37, No.10, pp.41-54.

10.7843/KGS.2021.37.10.41
4

Cho, S. E. (2022), “Applicability of Practical Reliability Analysis to Develop Fragility Curves for Levee”, Journal of the Korean Geotechnical Society, Vol.38, No.11, pp.19-30.

10.7843/KGS.2022.38.11.19
5

Cho, S. E. (2023), “Development of Fragility Curves for Slope Stability of Levee under Rapid Drawdown”, Journal of the Korean Geotechnical Society, Vol.39, No.10, pp.27-39.

10.7843/KGS.2023.39.10.27
6

Guardiani, C., Soranzo, E. and Wu, W. (2022), “Time-dependent Reliability Analysis of Unsaturated Slopes under Rapid Drawdown with Intelligent Surrogate Models”, Acta Geotechnica, Vol.17, No.4, pp.1071-1096.

10.1007/s11440-021-01364-w
7

Jung, H., Kim, Y., Lee, M., Lee, S., Tamang, B., Heo, J. and Ahn, S. (2021), “Behavioral Characteristics and Safety Management Plan for Fill Dam During Water Level Fluctuation Using Numerical Analysis”, Journal of the Korean Geosynthetics Society, Vol.20, No.1, pp.45-55.

10.12814/JKGSS.2021.20.1.045
8

Kim, J., Kim, Y. and Satyanaga, A. (2023), “Instability of embankment slopes due to overflow and drawdown”, Water, Vol.15, No.19, 3402.

10.3390/w15193402
9

Lee, K. W., Park, J., Won, D., Hong, G. and Lee, K. (2026), “Prediction of Slope Safety Factors from Seepage Characteristics in River Embankments”, Journal of the Korean Geosynthetics Society, Vol.25, No.2, pp.11-24.

10.12814/JKGSS.2026.25.2.011
10

Li, D., Chen, Y., Lu, W. and Zhou, C. (2011), “Stochastic response surface method for reliability analysis of rock slopes involving correlated non-normal variables”, Computers and Geotechnics, Vol.38, No.1, pp.58-68.

10.1016/j.compgeo.2010.10.006
11

Meng, F., Pei, H., Ye, M. and He, X. (2024), “Stability Analysis of Reservoir Slope under Water-Level Drawdown Considering Stratigraphic Uncertainty and Spatial Variability of Soil Property”, Computers and Geotechnics, Vol.169, 106199.

10.1016/j.compgeo.2024.106199
12

Rossi, N., Bačić, M., Kovačević, M. S. and Librić, L. (2021), “Development of Fragility Curves for Piping and Slope Stability of River Levees”, Water, Vol.13, No.5, 738.

10.3390/w13050738
13

Siacara, A. T., Beck, A. T. and Futai, M. M. (2020), “Reliability analysis of rapid drawdown of an earth dam using direct coupling”, Computers and Geotechnics, Vol.118, 103336.

10.1016/j.compgeo.2019.103336
14

Simm, J. and Tarrant, O. (2018), “Development of fragility curves to describe the performance of UK levee systems”, In Proceedings of the Twenty-Sixth International Congress on Large Dams, Vienna, Austria, pp.1-7.

15

Sun, R., Reheman, Y., Wang, X., Fei, K., Zhou, J. and Jiao, D. (2024), “Failure probability analysis of high fill levee considering multiple uncertainties and correlated failure modes”, Scientific Reports, Vol.14, No.1, 9436.

10.1038/s41598-024-59762-538658631PMC11538530
16

USACE (1996), Risk-based Analysis for Flood Damage Reduction Studies, US Army Corps of Engineers, Engineer Manual 1110-2-1619.

17

USACE (1999), Risk-based analysis in Geotechnical Engineering for Support of Planning Studies, Engineering and Design, ETL1110-2-556.

18

Wang, X., Xia, X., Zhang, X., Gu, X. and Zhang, Q. (2022), “Probabilistic Risk Assessment of Soil Slope Stability Subjected to Water Drawdown by Finite Element Limit Analysis,” Applied Sciences, Vol.12, No.20, 10282.

10.3390/app122010282
19

Wu, Z., Chen, C., Zheng, Y., Chen, J., Bian, K. and Li, J. (2024), “Analysis of Seepage Failure Probability for High Core Rockfill Dams during Rapid Drawdown of Reservoir Water Level”, Journal of Hydrology, Vol.633, 131046.

10.1016/j.jhydrol.2024.131046
20

Xiu, D. and Karniadakis, G. E. (2002), “The Wiener-Askey polynomial chaos for stochastic differential equations”, SIAM Journal on Scientific Computing, Vol.24, No.2, pp.619-644.

10.1137/S1064827501387826
Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 25
  • No :3
  • Pages :31-48
  • Received Date : 2026-07-28
  • Revised Date : 2026-08-18
  • Accepted Date : 2026-08-24
  • DOI :https://doi.org/10.12814/jkgss.2026.25.3.031
Journal Informaiton Journal of the Korean Geosynthetics Society Journal of the Korean Geosynthetics Society
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close