The Effect of Initial Groundwater Table and Rainfall Wetting Towards Slope Stability (Case Study of Landslide in Tangkil Hamlet, Banaran Village, Pulung Subdistrict, Ponorogo Regency)

https://doi.org/10.22146/jcef.43804

Diana Ariesta(1*)

(1) Directorate General of Water Resources, Ministry of Public Works and Housing
(*) Corresponding Author

Abstract


Landslide is a natural phenomenon that can be controlled by a combination of various factors, such as topography, lithological condition, geological structure, water table, etc. Landslide is stated as a natural disaster if it causes casualties, direct losses and subsequent impacts of the initial destruction, as happened in Banaran Village, Ponorogo Regency. This study is aimed to examine the effects of initial groundwater table conditions and rainfall wetting on Banaran Village landslide. This study was conducted by assuming scenarios of initial groundwater table conditions. Soil parameters were obtained by testing soil samples in the laboratory. Infiltration parameters were acquired through permeability tests using the Philip-Dunne method, while areal rainfall was calculated using the Thiessen polygon method. In addition, slope stability modeling was calculated by using SLOPE/W while rainfall wetting analysis was carried out through SEEP/W. The analysis of Banaran Village landslide through these two numerical models was conducted by considering two conditions: 1) without rainfall and 2) with rainfall and infiltration. The analysis results imply that the landslide occurred in the initial groundwater table condition in scenario 3 with a safety factor of 1.008, and in a similar scenario with a safety factor of 0.973 when taking into account rainfall and infiltration. The results from SEEP/W and SLOPE/W indicate that the initial condition of the groundwater table highly influenced the decrease of the safety factor, while the wetting process did not cause a significant decrease of the safety factor.


Keywords


Landslide; Safety factor; Rainfall wetting

Full Text:

PDF


References

BNPB (2017) Laporan Bencana Longsor Ponorogo Dusun Tangkil Desa banaran Kecamatan Pulung. Jakarta.

Das, B. M. (1985) Advanced Soil Mechanics. New York: McGraw-Hill.

Dinas Pekerjaan Umum dan Penataan Ruang Kabupaten Ponorogo (2012) Peraturan Daerah Kabupaten Ponorogo No. 1 Tahun 2012 tentang Rencana Tata Ruang Wilayah kabupaten Ponorogo Tahun 2012-2032. Ponorogo.

GEO-SLOPE International Ltd (2012) ‘Stability Modeling with SLOPE/W’. Calgary: GEO-SLOPE International Ltd.

Handayani, T., Wulandari, S. and Wulan, A. (2014) ‘Pengaruh Muka Air Tanah Terhadap Kestabilan Lereng Menggunakan GEOSLOPE/W 7.12’, KOMMIT, pp. 409–415.

Hartono, U., Baharuddin and Brata, K. (1992) Peta geologi lembar Madiun, Jawaskala 1:100.000.

Muñoz-Carpena, R. et al. (2002) ‘Field Evaluation of the New Philip-Dunne Permeameter for Measuring Saturated Hydraulic Conductivity’, Soil Science, 167(1). Available at: https://journals.lww.com/soilsci/Fulltext/2002/01000/FIELD_EVALUATION_OF_THE_NEW_PHILIP_DUNNE.2.aspx.

Muntohar, A. S. and Liao, H.-J. (2009) ‘Analysis of rainfall-induced infinite slope failure during typhoon using a hydrological–geotechnical model’, Environmental Geology, 56(6), pp. 1145–1159. doi: 10.1007/s00254-008-1215-2.

Philip, J. R. (1993) ‘Approximate analysis of falling-head lined borehole permeameter’, Water Resources Research. John Wiley & Sons, Ltd, 29(11), pp. 3763–3768. doi: 10.1029/93WR01688.

Regalado, C. M. et al. (2005) ‘Simplified Method to Estimate the Green–Ampt Wetting Front Suction and Soil Sorptivity with the Philip–Dunne Falling-Head Permeameter’, Vadose Zone Journal. Madison, WI: Soil Science Society, 4, pp. 291–299. doi: 10.2136/vzj2004.0103.

Suprapto, Nurmasari, R. and Rosyida, A. (2017) ‘Analisis Penyebab Tanah Longsor di Kabupaten Ponorog (Studi : Dusun tangkil, Desa Banaran, Kecamatan Pulung)’, Jurnal Dialog Penanggulangan Bencana No. 2, 4, pp. 112–119.



DOI: https://doi.org/10.22146/jcef.43804

Article Metrics

Abstract views : 890 | views : 805

Refbacks

  • There are currently no refbacks.




Copyright (c) 2019 Journal of the Civil Engineering Forum


The content of this website is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
ISSN 5249-5925 (online) | ISSN 2581-1037 (print)
Jl. Grafika No.2 Kampus UGM, Yogyakarta 55281
Email : jcef.ft@ugm.ac.id
Web Analytics JCEF Stats