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

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.


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Cut slopes are intensely prone to weathering in the cause of excavation effects. Weathering effects can reduce strength of rocks and results in instabilities in the long run. By the reasons of rocks containing joints, fractures, faults, bedding planes and pore spaces, they are likely to be weathered because of wetting-drying cycles, climate changes, and chemical action of solutions absorbed. This study is mainly concerned with the slope stability analysis for sixteen permanent cut slopes that are composed o...
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Citation Formats
T. Ersöz and T. Topal, “Weathering and Excavation Effects on the Stability of Various Cut Slopes in Flysch-Like Deposits,” GEOTECHNICAL AND GEOLOGICAL ENGINEERING, pp. 3707–3729, 2018, Accessed: 00, 2020. [Online]. Available: