Analyses on variations in the unsaturated characteristics of a mine waste-dump slope during rainfall

  • Young-Suk Song
  • Yong-Chan ChoEmail author
  • Seongwon Hong
Original Article


Field measurement units and a system were constructed and installed in a waste-dump slope at the Imgi mine to investigate and analyze the variations in the unsaturated characteristics of the soil. The field instrumentation system was composed of a data acquisition system, a solar system, and measuring sensors. The rainfall, matric suction, and volumetric water contents were continuously measured from the units in the instrumented site and analyzed with the soil water characteristic curve (SWCC) estimated from laboratory experiments. The variations in matric suction and volumetric water content were primarily affected by the rainfall intensity. At the surface of the slope, the largest increase and decrease in the changes in matric suction and volumetric water content were observed during the wetting and drying processes, respectively. The matric suction and volumetric water content measured from the instrumented area were compared with the SWCCs obtained from the laboratory test, and the measured data were located between the drying and wetting paths. The drying and wetting paths obtained from the laboratory test are regarded as primary drying and wetting curves, respectively. Therefore, the measured data can be defined as scanning curves, which are located between primary drying and wetting curves. The variations in matric suction according to volumetric water content were dependent on depth, and a wide range of variations was observed at shallow depths. It was confirmed that the unsaturated soil near the ground surface has the sensitive reaction induced by the infiltration and evaporation in nature.


Field monitoring Matric suction Rainfall Volumetric water content Waste-dump slope 



This research was supported by the Basic Research Project (Grant No. 16-3413) of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science, ICT, and Future Planning of Korea.


  1. Chae BG, Seo YS (2012) An alternative method for landslide early warning based on gradient of volumetric water content in unsaturated soil. Proc XI international symposium on Landslides, Banff, Alberta, Canada, vol 2, pp 1457–1463Google Scholar
  2. Cho SE, Lee SR (2001) Instability of unsaturated soil slopes due to infiltration. Comput Geotech 28:185–208. doi: 10.1016/S0266-352X(00)00027-6 CrossRefGoogle Scholar
  3. Comegna L, Damiano E, Greco R, Guida A, Olivares L, Picarelli L (2016) Field hydrological monitoring of a sloping shallow pyroclastic deposit. Can Geotech J 53:1–13. doi: 10.1139/cgj-2015-0344 CrossRefGoogle Scholar
  4. Damiano E, Olivares L, Picarelli L (2012) Steep-slope monitoring in unsaturated pyroclastic soils. Eng Geol 137–138:1–12. doi: 10.1016/j.enggeo.2012.03.002 CrossRefGoogle Scholar
  5. Feng M, Fredlund DG (1999) Hysteretic influence associated with thermal conductivity sensor measurements. Proc from theory to the practice of unsaturated soil mechanics, in association with 52nd Can Geotech Conf and Unsaturated Soil Group, Regina, Canada, pp 14:2:14–14:2:20Google Scholar
  6. Fredlund DG, Rahardjo H (1993) Soil mechanics for unsaturated soils. Wiley, New YorkCrossRefGoogle Scholar
  7. Gasmo J, Hritzuk KJ, Rahardjo H, Leong EC (1999) Instrumentation of an unsaturated residual soil slope. Geotech Test J 22:128–137Google Scholar
  8. Godt JW, Baum RL, Lu N (2009) Landsliding in partially saturated materials. Geophys Res Lett. doi: 10.1029/2008GL035996 Google Scholar
  9. Griffiths DV, Lu N (2005) Unsaturated slope stability analysis with steady infiltration or evaporation using elasto-plastic finite elements. Int J Numer Anal Meth Geomech 29:249–267. doi: 10.1002/nag.413 CrossRefGoogle Scholar
  10. Harris SJ, Orense RP, Itoh K (2012) Back analysis of rainfall-induced slope failure in Northland Allochthon formation. Landslides 9:349–356. doi: 10.1007/s10346-011-0309-1 CrossRefGoogle Scholar
  11. Hilf JW (1956) An investigation of pore water pressure in compacted cohesive soils. Technical memorandum, no. 654. U.S. Department of the interior, Bureau of Reclamation, Design and Construction Division, Denver, COGoogle Scholar
  12. Kim MI, Chae BG, Cho YC, Seo YS (2008) Study on rainfall infiltration characteristics for weathered soils: analysis of soil volumetric water content and its application. J Eng Geol 18:83–92 (In Korean with English abstract) Google Scholar
  13. Lee IM, Cho WS, Kim YU, Sung SG (2003) In-situ monitoring of matric suctions in a weathered soil slope. J Korean Geotech Soc 19(1):41–49 (In Korean with English abstract) Google Scholar
  14. Li AG, Yue ZQ, Tham LG, Lee CF, Law KT (2005) Field-monitored variations of soil moisture and matric suction in a saprolite slope. Can Geotech J 42:13–26. doi: 10.1139/T04-069 CrossRefGoogle Scholar
  15. Lim TT, Rahardjo H, Chang MF, Fredlund DG (1996) Effect of rainfall on matric suctions in a residual soil slope. Can Geotech J 33:618–628. doi: 10.1139/T96-087 CrossRefGoogle Scholar
  16. Lu N, Likos WJ (2004) Unsaturated soil mechanics. Wiley, New YorkGoogle Scholar
  17. Mofiz SA, Sarkar DC, Rahman S, Awall MR, Taha MR, Hossain MK (2005) Instrumentation and matric soil suction measurement in a decomposed granite soil slope. Proc of the advanced experimental unsaturated soil mechanics, Trento, Italy, pp 527–532Google Scholar
  18. Muraleetharan KK, Liu C, Wei C, Kibbey TCG, Chen L (2009) An elastoplastic framework for coupling hydraulic and mechanical behavior of unsaturated soils. Int J Plast 25:473–490. doi: 10.1016/j.ijplas.2008.04.001 CrossRefGoogle Scholar
  19. Ng CWW, Shi Q (1998) A numerical investigation of the stability of unsaturated soil slopes subjected to transient seepage. Comput Geotech 22:1–28. doi: 10.1016/S0266-352X(97)00036-0 CrossRefGoogle Scholar
  20. Oh SB, Lu N (2015) Slope stability analysis under unsaturated conditions: case studies of rainfall-induced failure of cut slopes. Eng Geol 184:96–103. doi: 10.1016/j.enggeo.2014.11.007 CrossRefGoogle Scholar
  21. Rahardjo H, Lee TT, Leong EC, Rezaur RB (2005) Response of a residual soil slope to rainfall. Can Geotech J 42:340–351. doi: 10.1139/T04-101 CrossRefGoogle Scholar
  22. Rahardjo H, Leong EC, Rezaur RB (2008) Effect of antecedent rainfall on pore-water pressure distribution characteristics in residual soil slopes under tropical rainfall. Hydrol Process 22:506–523. doi: 10.1002/hyp.6880 CrossRefGoogle Scholar
  23. Rahardjo H, Satyanaga A, Leong E (2013) Effects of flux boundary conditions on pore-water pressure distribution in slope. Eng Geol 165:133–142. doi: 10.1016/j.enggeo.2012.03.017 CrossRefGoogle Scholar
  24. Smith JB, Godt JW, Baum RL, Coe JA, Burns WJ, Lu N, Morse MM, Sener-Kaya B, Kaya M (2014) Hydrologic monitoring of a landslide-prone hillslope in the Elliott State Forest, Southern Coast Range, Oregon, 2009–2012: U.S. Geological Survey Open-File Report 2013–1283, p 61. doi: 10.3133/ofr20131283
  25. Song YS, Lee NW, Hwang WK, Kim TH (2010) Construction and application of an automated apparatus for calculating the soil-water characteristics curve. J Korean Geotech Soc 20:281–295 (In Korean with English abstract) Google Scholar
  26. Song YS, Hong WP, Woo KS (2012a) Behavior and analysis of stabilizing piles installed in a cut slope during heavy rainfall. Eng Geol 129–130:56–67. doi: 10.1016/j.enggeo.2012.01.012 CrossRefGoogle Scholar
  27. Song YS, Hwang WK, Jung SJ, Kim TH (2012b) A comparative study of suction stress between sand and silt under unsaturated conditions. Eng Geol 124:90–97. doi: 10.1016/j.enggeo.2011.10.006 CrossRefGoogle Scholar
  28. Trandafir AC, Sidle RC, Gomi T, Kamai T (2008) Monitored and simulated variations in matric suction during rainfall in a residual soil slope. Environ Geol 55:951–961. doi: 10.1007/s00254-007-1045-7 CrossRefGoogle Scholar
  29. Tsaparas I, Rahardjo H, Toll DG, Leong EC (2003) Infiltration characteristics of two instrumented residual soil slopes. Can Geotech J 40:1012–1032. doi: 10.1139/T03-049 CrossRefGoogle Scholar
  30. Tu XB, Kwong AKL, Dai FC, Tham LG, Min H (2009) Field monitoring of rainfall infiltration in a loess slope and analysis of failure mechanism of rainfall-induced landslides. Eng Geol 105:134–150. doi: 10.1016/j.enggeo.2008.11.011 CrossRefGoogle Scholar
  31. van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:892–898. doi: 10.2136/sssaj1980.03615995004400050002x CrossRefGoogle Scholar
  32. Wayllace A, Lu N (2012) A transient water release and imbibitions method for rapidly measuring wetting and drying soil water retention and hydraulic conductivity functions. Geotech Test J 35(1):GTJ103596CrossRefGoogle Scholar
  33. Zhan TLT, Ng CWW, Fredlund DG (2007) Field study of rainfall infiltration into a grassed unsaturated expansive soil slope. Can Geotech J 44:392–408. doi: 10.1139/T07-001 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Geologic Environment DivisionKorean Institute of Geoscience and Mineral ResourcesDaejeonKorea
  2. 2.Engineering Research InstituteSeoul National UniversitySeoulKorea

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