A.A. Muliaprasanti1, F. Faris1*
1Department of Civil and Environmental Engineering, Gadjah Mada University, Yogyakarta, INDONESIA
*Corresponding author: fikri.faris@ugm.ac.id
Assessment of Liquefaction Potential in Coastal Soil Deposits Based on Simplified Procedure and Finite Element Modeling
A.A. Muliaprasanti(1), F. Faris(1)*
1Department of Civil and Environmental Engineering, Gadjah Mada University, Yogyakarta, INDONESIA
*Corresponding author: fikri.faris@ugm.ac.id
ABSTRACT
Indonesia is located in a tectonically active region due to the interaction of the Indo-Australian, Eurasian, and Pacific plates, making it highly susceptible to earthquake-induced hazards such as liquefaction. The 2018 Sulawesi earthquake highlighted the significant impact of liquefaction in saturated coastal deposits around Palu Bay, which contributed to severe ground deformation and tsunami generation. This study evaluates the liquefaction potential in the Labuan area, Central Sulawesi, located near the Palu–Koro Fault and characterized by young Quaternary deposits with shallow groundwater conditions. Liquefaction susceptibility was assessed using the Simplified Procedure based on Standard Penetration Test (SPT), complemented by the Liquefaction Potential Index (LPI) and Liquefaction Severity Index (LSI). Numerical modeling using the Finite Element Method implemented in RS2 was also conducted to evaluate the development of excess pore water pressure
ratio (ru) during seismic loading. The results indicate that most soil layers exhibit factors of safety (FS) values greater than 1,2, suggesting generally stable conditions. A potentially vulnerable layer occurs at approximately 5 m depth with FS ≈ 1,11; however, ru values remain below the liquefaction threshold, and LPI–LSI results indicate low overall liquefaction susceptibility. These findings suggest that liquefaction potential at the site is localized but should be considered in coastal seismic hazard assessments.
REFERENCES
Earthquake Engineering Research Group INHA University. (2025). PRISM for Earthquake Engineering (Version 2025) [Computer software]. INHA University.
Hardiyatmo, H. C. (2022). Rekayasa Gempa untuk Analisis Struktur dan Geoteknik (1st ed.). Gadjah Mada University Press.
Huang, Y., & Yu, M. (2013). Review of soil liquefaction characteristics during major earthquakes of the twenty-first century. Natural Hazards, 65(3), 2375–2384. https://doi.org/10.1007/s11069-012-0433-9
Idriss, I. M., & Boulanger, R. W. (2014). CPT and SPT-Based Liquefaction Triggering Procedures (UCD/CGM-14/01). Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CA.
Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). (2018). Time History of Palu Earthquake 2018. Indonesian Agency for Meteorology, Climatology, and Geophysics, Balaroa.
Iwasaki, T., Tokida, K., & Tatsuoka, F. (1982). Soil Liquefaction Potential Evaluation with Use of the Simplified Procedure. Proceeding of the Conference on Soil Dynamics and Earthquake Engineering, 925–939.
JICA Project Team, PT. Geomarindex, Budi Ferizqianto, Renaldo Afwan, Daniel Girsang, & Frans Segar Gultom. (2019). Geotechnical Invetigation of Landslide Palu Area. JICA.
J.R. Gingery, A. Elgamal, & J.D.Bray. (2015). Liquefaction model calibration: Element-level versus 1-D site response. 6th
International Conference on Earthquake Geotechnical Engineering. https://www.issmge.org/publications/online-library
Kien Dang, Alireza Azami, & Rocscience. (2024). Case Study RS2: Undrained Analysis of a Deep Excavation in Clayey Soils Using PLAXIS Hardening Soil Model
in RS2. Rocscience Inc. https://www.rocscience.com/learning/undrained-analysis-for-deep-excavation-in-clayey-soils-using-rs2
Kuhlemeyer, R. L. & Lysmer, J. (1973). Finite Element Method Accuracy for Wave Propagation Problems. Journal of the Soil Mechanics and Foundations Division, 99(5), 421–427.
Liu, P. L. F., Higuera, P., Husrin, S., Prasetya, G. S., Prihantono, J., Diastomo, H., Pryambodo, D. G., & Susmoro, H. (2020). Coastal landslides in Palu Bay during 2018 Sulawesi earthquake and tsunami. Landslides, 17(9), 2085–2098. https://doi.org/10.1007/s10346-020-01417-3
Look, B. (2007). Handbook of geotechnical investigation and design tables. Taylor & Francis.
Nath, S. K., & Thingbaijam, K. K. S. (2009). Seismic hazard assessment – a holistic microzonation approach. Natural Hazards and Earth System Sciences, 9(4), 1445–1459. https://doi.org/10.5194/nhess-9-1445-2009
National Standardization Agency of Indonesia (BSN). (2017). SNI 8460-2017 Persyaratan Perancangan Geoteknik (SNI 8460:2017). National Standardization Agency of Indonesia (BSN).
Özener, P. T., Özaydın, K., & Berilgen, M. M. (2009). Investigation of liquefaction and pore water pressure development in layered sands. Bulletin of Earthquake Engineering, 7(1), 199–219. https://doi.org/10.1007/s10518-008-9076-3
Primadika, R. A. (2025). Seismic Response Evaluation And Design Of Tunnel Crossing Fault Fracture Zone. Gadjah Mada University.
Rocscience. (2024a). RS 2 Documentation: Undrained Behaviour of Soil. Rocscience Inc. https://www.rocscience.com/help/rs2/documentation/rs2 model/material-properties/define-hydraulic-properties/undrained-behaviour/undrained-behaviour-of-soil
Rocscience. (2024b). RS2 Documentation: Groundwater. Rocscience Inc. https://www.rocscience.com/help/rs2/documentation/rs2-model/project-settings/groundwater
Rocscience. (2024c). Undrained Behavior. Rocscience Inc. https://www.scribd.com/document/512029006/Un-Drained
Sassa, S., & Takagawa, T. (2019). Liquefied gravity flow-induced tsunami: First evidence and comparison from the 2018 Indonesia Sulawesi earthquake and tsunami disasters. Landslides, 16(1), 195–200. https://doi.org/10.1007/s10346-018-1114-x
Schambach, L., Grilli, S. T., & Tappin, D. R. (2021). New High-Resolution Modeling of the 2018 Palu Tsunami, Based on Supershear Earthquake Mechanisms and Mapped Coastal Landslides, Supports a Dual Source. Frontiers in Earth Science, 8, 598839. https://doi.org/10.3389/feart.2020.598839
Setiawan, Y. (2024). Non-linear Analysis of Pile Foundation in Liquefiable Soil Using Dynamic Constitutive Model and Seismic Hazard Analysis. Gadjah Mada University.
Sitharam, T. G., & Vipin, K. S. (2010). Liquefaction Potential Evaluation Based On Site Classes – A Performance Based Approach. International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, 7.
Socquet, A., Simons, W., Vigny, C., McCaffrey, R., Subarya, C., Sarsito, D., Ambrosius, B., & Spakman, W. (2006). Microblock rotations and fault coupling in SE Asia triple junction (Sulawesi, Indonesia) from GPS and earthquake slip vector data. Journal of Geophysical Research: Solid Earth, 111(B8), 1–15. https://doi.org/10.1029/2005JB003963
Sonmez, H. (2003). Modification of the liquefaction potential index and liquefaction susceptibility mapping for a liquefaction-prone area (Inegol,Turkey). Environmental Geology, 44(7), 862–871. https://doi.org/10.1007/s00254-003-0831-0
Sonmez, M., & Gokceoglu, C. (2005). A Liquefaction Severity Index Suggested for Engineering Practice. Evirontmental Geology, 48(2), 81–91.
Sukamto, R., Sumardirdia, H., & Pusat Penelitian dan Pengembangan Geologi (Indonesia). (1973). Peta Geologi Lembar Palu [Map]. Pusat Penelitian dan Pengembangan Geologi (Indonesia).
Upadhyaya, S., Green, R. A., Rodriguez-Marek, A., & Maurer, B. W. (2019). Selecting factor of safety against liquefaction for design based on cost considerations. Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions, 5419–5426.
Watkinson, I. M. (2011). Ductile flow in the metamorphic rocks of central Sulawesi. Geological Society Special Publication, 355, 157–176. https://doi.org/10.1144/SP355.8