Environmental Geology

, Volume 46, Issue 1, pp 83–95 | Cite as

Evaluation of rock excavatability and slope stability along a segment of motorway, Pozanti, Turkey

  • B. Kentli
  • T. Topal
Original Article


The Çiftehan-Pozantı segment of the Ankara-Pozantı motorway is problematic due to the existence of lithological units with variable character. Seven cut slopes are planned along Km 358+000– Km 364+350 of the proposed motorway. The purpose of this study is to determine engineering geological properties of the rocks exposed along the motorway and to assess the excavatability and stability of the cut slopes. Both field and laboratory studies were carried out during this study. Field studies involved geological mapping, detailed discontinuity surveying and sampling. Laboratory tests were carried out to determine unit weight, point load strength index and shear strength parameters of the discontinuities. In the study area, recrystallized limestone, microgabbro, conglomerate and Quaternary deposits are exposed. However, the cut slopes are located within microgabbro and conglomerate. Hard to very hard ripping with local blasting for the fresh inner part of the rocks is recommended for the excavatability. In two cut slopes wedge failure is expected, whereas in another two slopes both wedge and toppling failures are likely to occur. Based on the field observations and stability analyses of the cut slopes, slope flattening with various angles, wire mesh, and drainage ditches are proposed.


Ankara-Pozantı Motorway Ease of excavatation Kinematic analysis Limit equilibrium Rock slope 



The authors gratefully acknowledge PETRA Ltd. Sti. and Yavuz Ergintav for their helps during the field and office studies.


  1. Bieniawski ZT (1989) Engineering rock mass classifications. Wiley, New YorkGoogle Scholar
  2. Caterpillar (1988) Caterpillar performance handbook, 19th edn. Caterpillar Tractor Company, Peoria, Illinois, USAGoogle Scholar
  3. Demirtaslı E, Turan N, Bilgin AZ (1986) Bolkar Dağları ile Ereğli-Ulukışla Havzasının Genel Jeolojisi. MTA, Jeoloji Etütleri DairesiGoogle Scholar
  4. Franklin JA, Broch E, Walton G (1971) Logging the mechanical character of rock. Trans Inst Mining Metall 80A, pp 1–9Google Scholar
  5. GDDA (1996) Earthquake zoning map of Turkey, General Directorate of Disaster Affairs, Ministry of Reconstruction and Resettlement of TurkeyGoogle Scholar
  6. Goodman RE (1989) Introduction to rock mechanics, 2nd edn, Wiley, New YorkGoogle Scholar
  7. Gülkan P, Yücemen S, Koçyiğit A, Doyuran V, Başöz N (1993) En son verilere gore hazırlanan Türkiye deprem bölgeleri haritası, ODTÜ Deprem Mühendisliği Araştırma Merkezi, Rapor No. 93–01Google Scholar
  8. Hadjigeorgiou J, Scoble MJ (1990) Ground characterization for assessment of ease of excavation. In: Singhal RK, Vavra M (eds) Proceedings of the 4th International Symposium on Mine Planning and Equipment Selection, Calgary, Balkema, Rotterdam, pp 323–331Google Scholar
  9. Hoek E, Bray JW (1981) Rock slope engineering. Inst Min Metall, Revised 3rd edn, LondonGoogle Scholar
  10. ISRM (1981) Rock characterization, testing and monitoring. Brown ET (ed) International Society for Rock Mechanics (ISRM) Suggested Methods, Pergamon Press, OxfordGoogle Scholar
  11. ISRM (1985) Point load test, suggested method for determining point load strength: Int J Rock Mech, Mining Sci Geomech Abstr 22:51–60Google Scholar
  12. Karpuz C, Paşamehmetoğlu AG, Bozdağ T, Müftüoğlu Y (1990) Rippability assessment in surface coal mining: In: Singhal RK, Vavra M (eds) Proceedings of the 4th International Symposium on Mine Planning and Equipment Selection, Calgary, Balkema, Rotterdam, pp 315–322Google Scholar
  13. Kentli B (2002) Assessment of excavatability and slope stability for Çiftehan-Pozantı segment of the Ankara-Pozantı motorway, MSc Thesis, METU, Ankara (unpublished)Google Scholar
  14. Kirsten HAD (1982) A classification system for excavation in natural materials. The Civil Engineer in South Africa 24:293–308Google Scholar
  15. Koçyiğit A, Beyhan A (1998) A new intracontinental transcurrent structure: the Central Anatolian Fault Zone, Turkey. Tectonophysics. 284(3–4):317–336Google Scholar
  16. MacGregor F, Fell R, Mostyn GR, Hocking G, McNally G (1994) The estimation of rock rippability. Q J Eng Geol 27:123–144Google Scholar
  17. Marcuson WF, Franklin AG (1983) Seismic design analysis and remedial measures to improve the stability of existing earth dams, Corps of Engineers Approach, Seismic Design of Embankments and Caverns, T.R. Howard (ed) New York, ASCEGoogle Scholar
  18. Minty EJ, Kearns GK (1983) Rock mass workability. In: Knight MJ, Minty EJ, Smith RB (eds) Collected case studies in engineering geology. Geol Soc Austr Spec Publ 11:59–81Google Scholar
  19. Pettifer GS, Fookes PG (1994) A revision of the graphical method for assessing the excavability of rock. Q J Eng Geol 27:145–164Google Scholar
  20. Rocscience (1999a) DIPS 5.0-Graphical and statistical analysis of orientation data. Rocscience Inc., CanadaGoogle Scholar
  21. Rocscience (1999b) Swedge 3.0- Surface wedge analysis. Rocscience Inc., CanadaGoogle Scholar
  22. Scoble MJ, Muftuoğlu YV (1984) Derivation of a diggability index for surface mine equipment selection. Min Sci Technol 1:305–322Google Scholar
  23. Singh RN, Denby B, Egretli I (1987) Development of a new rippability index for coal measures excavations. Proceedings of the 28th U.S. Symposium on Rock Mechanics, Tuscon, Arizona. Balkema, Boston, pp 935–943Google Scholar
  24. Smith HJ (1986) Estimating rippability by rock mass classification. Proceedings of the 27th U.S. Symposium on Rock Mechanics, Tuscaloosa, Alabama. AIME, New York, pp 443–448Google Scholar
  25. Turner AK, Schuster RL (1996) Landslides-investigation and mitigation. Transportation Research Board, National Research Council, Spec Rep 247. National Academy Press, Washington, DCGoogle Scholar
  26. USGS (2002) NEIC: Earthquke search: rectangular Area. US Geological Survey
  27. Weaver JM (1975) Geological factors significant in the assessment of rippability. The Civil Engineer in South Africa 17:313–316Google Scholar
  28. Yetiş C (1984) New observations on the age of the Ecemiş Fault. Proc. of International Symposium on the Geology of the Taurus Belt, Ankara-Turkey, pp159–164Google Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Department of Geological EngineeringMiddle East Technical UniversityAnkaraTurkey

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