An approach on modelling of in-situ deformations for unstable coal mine slopes

  • Hakan ÖzşenEmail author
  • İhsan Özkan
  • Mehmet Mesutoğlu
Original Article


Twelve unstable slopes have been observed in four different coal mines of the General Directorate of Turkey Coal Enterprises (TKİ) for the last 12 years. A total of 131 theodolite, inclinometer and extensometer stations have been established for monitoring unstable slopes. According to the measurement results, the magnitude of the deformation values in all of the stations ranges from 0 to 10,978 mm. The database shows that time dependent deformation is formed in three consecutive stages. The form of the first stage is logarithmic, the second stage is linear and the third stage is exponential. To ensure control of the unstable slope, precautions must be taken during the second stage, or the beginning of the third stage at the latest according to observations, measurements and previous experience. To express time dependent deformation behaviour for unstable slopes, a graphical presentation of the mathematical model was developed. By means of statistical analysis of the database, a mathematical model was prepared. The model is characterized by three stages of deformation behaviour. In addition, the model can be presented in sub-deformation curves for each stage. The sum of the sub-deformation curves are equal to the predicted deformation curve. However, in this study, it is named as the predicted total deformation. Velocity and acceleration behaviours were determined by taking first and second derivatives of the time dependent predicted total deformation curve. Therefore, all stages of the deformation can be determined. In addition, a classification based on deformation behaviour for unstable slopes was suggested.


Slope stability In situ measurements Deformation behaviour Mathematical modelling 



This study was supported by the Research Foundation of Selçuk University and TKİ. The authors are also indebted to the reviewers for their valuable comments.


  1. Anon (2003a) Monitoring unstable slopes in TKİ-GLİ-Orhaneli open pit mine. Technical ReportGoogle Scholar
  2. Anon (2003b) Monitoring unstable slopes in TKİ-GELİ-Eskihisar open pit mine. Technical ReportGoogle Scholar
  3. Anon. (2010) Monitoring unstable slopes in TKİ-GELİ-Eskihisar open pit mine. Technical ReportGoogle Scholar
  4. Duncan JM (1996) State of the art: limit equilibrium and finite-element analysis of slopes. J Geotech Eng 122:577–596. CrossRefGoogle Scholar
  5. Gökay M, Özkan İ, Özşen H, Doğan K, Mesutoğlu M (2013) TKİ-GLİ-BLİ In-situ field measurements and evaluations for slope stability analysis in Gümüşpınar open pit. TKI Final Project Report, Selçuk University, Department of Mining Engineering, Konya, Turkey; 326p (in Turkish)Google Scholar
  6. İnci U, Koçyiğit A, Bozkurt E, Arpalıyiğit İ (2001) Kinematic analysis and seismicity of edge faults at Kırkağaç and Soma (Manisa) grabens. TUBITAK, Project No. YDABÇAG-199Y013; 73p (in Turkish)Google Scholar
  7. Karapınar GK (2011) Distribution, reserve and some operation parameters of North Kisrakdere (Soma) coal. MSc thesis, Balıkesir University, Balıkesir, Turkey, p 142 (in Turkish)Google Scholar
  8. Kim J, Lee S (1997) An improved search strategy for the critical slip surface using finite element stress fields. Comput Geotech 21:295–313. CrossRefGoogle Scholar
  9. Mesutoğlu M (2013) Mathematical analysis for in-situ deformations obtained from inclinometer measurement boreholes established inside rock and soil structures. MSc thesis, Selçuk University, Konya, Turkey, p 215 (in Turkish)Google Scholar
  10. Mıh M (2011) Monitoring of slope stable by inclinometer and settlement tube devices of CG-1 panel at TKI-GLI-Ilgin Lignite Operation. MSc thesis, Selçuk University, Konya, Turkey, p 149 (in Turkish)Google Scholar
  11. Özkan İ (1995) Modified rock mass rating (M-RMR) system and roof behavior model. PhD thesis, Middle East Technical University (METU), Ankara, Turkey, p 398Google Scholar
  12. Özkan İ (2014) Mathematical approach for the analysis of in situ measurements in unstable slopes: a study based on the cases from coal mines in Turkey. In: Alejano R, Perucho Á, Olalla C, Jiménez R (eds) EUROCK 2014 regional symposium: rock engineering and rock mechanics: structures in and on rock masses, Vigo. CRC Press, Spain, pp 725–730Google Scholar
  13. Özkan İ, Pektaş A, Özşen H (2006a) Comparing different approaches developed for circular failure in slopes. Paper presented at the 15th Coal Congress of Turkey, ZonguldakGoogle Scholar
  14. Özkan İ, Uslu S, Özşen H (2006b) Long-term slope deformation measurement in TKI-Yatagan-Eskihisar lignite open pit mine. Paper presented at the Regional Rock Mechanics Symposium, IstanbulGoogle Scholar
  15. Özkan İ, Mıh M, Kahveci S, Kaya İ (2011a) Long-term slope deformation measurements by borehole in TKİ-GLİ-Ilgın open pit coal mine. Paper presented at the ROCMEC2011-Xth Regional Rock Mechanics Symposium, AnkaraGoogle Scholar
  16. Özkan İ, Özşen H, Oltulu F, Boztaş S (2011b) Mathematical model based on long term inclinometer measurements at an open pit limestone mine. Paper presented at the 2nd Conference on Slope Tectonics, ViennaGoogle Scholar
  17. Özşen H (2009) Determining short and long term mechanical properties and mathematical modelling of rock salt. PhD thesis, Selçuk University, Konya, Turkey p 340 (in Turkish)Google Scholar
  18. Özşen H (2010) Monitoring unstable slopes in TKI-GLI-Ilgın open-pit mine. Selçuk University Department of Mining Engineering; Technical Report; p 18Google Scholar
  19. Özşen H, Kaklık H (2011) Eskihisar-monitoring in unstable open-pit slopes. Selçuk University Department of Mining Engineering; Technical Report; p 18Google Scholar
  20. Özşen H, Kurt AC (2015) Monitoring deformations formed in Soma lignite open pit mine by ınclinometer method. Selcuk Univ. J Eng Sci Technol 3:59–65Google Scholar
  21. Özşen H, Özkan İ (2013) Deformation monitoring and time dependent mathematical modeling of the tension cracks at the western slopes of TKI-GLI Ilgın open lignite mine. Selcuk Univ. J Eng Sci Technol 1:37–44Google Scholar
  22. Pektaş A (2005) Determination of weak, stratified, clay-bearing and anisotropic rock mass characterization in TKI-Ilgın lignite open pit mine and slope stability analysis. MSc thesis, Selçuk University, Konya, Turkey, p 213 (in Turkish)Google Scholar
  23. Piccinini L, Berti M, Simoni A, Bernardi A, Ghirotti M, Gargini A (2014) Slope stability and groundwater flow system in the area of Lizzano in belvedere (northern Apennines, Italy). Eng. Geo 183:276–289. CrossRefGoogle Scholar
  24. Pinheiro M, Sanches S, Miranda T, Neves A, Tinoco J, Ferreira A, Correia AG (2015) A new empirical system for rock slope stability analysis in exploitation stage. Int J Rock Mech Min Sci 76:182–191. CrossRefGoogle Scholar
  25. Qiao L, Li Y (2004) Engineering geological model of high-steep slope damage in Opencut mines. J Univ Sci Technol Beijing 26:461–464Google Scholar
  26. Ulusay R, Hudson JA (2007) The complete ISRM suggested methods for rock characterization, testing and monitoring: 1974–2006. ISRM Turkish National Group, AnkaraGoogle Scholar
  27. Ulusay R, Ekmekci M, Tuncay E, Hasancebi N (2014) Improvement of slope stability based on integrated geotechnical evaluations and hydrogeological conceptualisation at a lignite open pit. Eng Geo 181:261–280. CrossRefGoogle Scholar
  28. Ünal E, Özkan I, Çakmakci G (2001) Modeling the behavior of longwall coal mine gate roadways subjected to dynamic loading. Int J Rock Mech Min Sci 38:181–197. CrossRefGoogle Scholar
  29. Uslu S (2005) Determination of rock mass characterization in TKİ-GELİ-Yatağan-Eskihisar lignite open pit mine and slope stability analysis. MSc thesis, Selçuk University, Konya, Turkey, p 182 (in Turkish)Google Scholar
  30. Varnes DJ (1978) Slope movement types and processes. In: Schuster RL, Krizek RJ (eds) Special report 176: landslides: analysis and control. Transportation and Road Research Board, National Academy of Science, Washington D. C, pp 11–33Google Scholar
  31. Wieczorek GF (1984) Preparing a detailed landslide-inventory map for hazard evaluation and reduction. Bull Assoc Eng Geol 21:337–342Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Hakan Özşen
    • 1
    Email author
  • İhsan Özkan
    • 1
  • Mehmet Mesutoğlu
    • 1
  1. 1.Department of Mining Engineering, Faculty of EngineeringSelçuk UniversityKonyaTurkey

Personalised recommendations