Stability of earth slopes under the effect of main environmental properties of weathered clay–marl deposits in Belgrade (Serbia)

Abstract

In the present paper, the impact of the main environmental factors on slope stability is analyzed by deriving a model for slope safety factor as a nonlinear function of geomechanical soil properties (bulk density γ, cohesion c, angle of internal friction φ and pore water pressure coefficient r u ) and terrain geometry (slope height H, bedrock depth d and slope angle β). The suggested model is derived using the response surface method, based on Spencer’s stability analyses of homogeneous slopes with circular slip surface. The analyzed parameter ranges were chosen according to the commonly determined values for unstable slopes in Neogene clay–marl deposits in Belgrade. The statistical reliability of the suggested model was confirmed by analyzing the stability of slopes with random geomechanical soil properties and terrain geometry. The obtained results indicate that all the examined environmental factors have statistically significant impact on the slope stability with prevailing linear effect, while geometrical factors and cohesion also show substantial quadratic effect. The existence of two-factor interactions imply that the impact of slope height on its stability is strongly dependent on slope angle, cohesion and bedrock depth, while the latter two also significantly affect the impact of slope angle on F s .