Weathering and Excavation Effects on the Stability of Various Cut Slopes in Flysch-Like Deposits


GEOTECHNICAL AND GEOLOGICAL ENGINEERING, vol.36, no.6, pp.3707-3729, 2018 (ESCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 36 Issue: 6
  • Publication Date: 2018
  • Doi Number: 10.1007/s10706-018-0566-z
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus
  • Page Numbers: pp.3707-3729
  • Keywords: Cut-slope, Degradation, Excavation, Flysch, Slope stability, Weathering, WEAK ROCK MASSES, BEHAVIOR
  • Middle East Technical University Affiliated: Yes


Cut slopes are very sensitive to weathering because of disturbed rock mass and topographical condition by excavation. During and right after an excavation process of a cut slope, weathering and erosion may act on this newly exposed rock material and mass. These acting on the rock may degrade and change its engineering properties and the stability of the cut slope in its engineering lifetime. In this study, weathering and excavation effects on stability of sixteen cut slopes in flysch-like deposits at North West Black Sea region of Turkey were investigated. The properties of the weathered and fresh rock materials including unit weight, uniaxial compressive strength, direct shear, slake durability and methylene blue tests were determined in the laboratory. Kinematic, limit equilibrium and rockfall analyses were performed for each stop. It was found that two testing cycles are insufficient to assess the degradation of the rocks based on the slake durability test results. Based on the limit equilibrium analyses, plane failure is expected with low factor of safety in one of the cut slopes. Factor of safeties of the cut slopes for mass failure are generally high except two slopes also evidenced with the field observations. No significant rockfall problems are expected according to the analyses. The effects of weathering and excavation were found to be changing between 10 and 50cm in average within 5years lifespan of the cut slopes. According to the results these disturbed zones would only create surficial degradation for the current thicknesses.