Probabilistic Slope Stability Analysis: A Case Study

Probabilistic slope stability analyses are becoming more and more popular to evaluate the safety level of slopes and associated risk and reliability, especially in the recent years. The probabilistic approach can take into account the uncertainties and natural variability in material properties, as well as in environmental factors, by using various statistical distribution functions (such as normal, lognormal etc.) for random variables. It is already noted by various researchers that, a slope with a deterministic factor of safety larger than 1.00 using average values of soil parameters may have a significant level of probability of failure, if the material properties are unknown, or contain significant uncertainty/variability. In this study, a well-documented landslide case study is used to demonstrate the importance of probabilistic approach in slope stability; to investigate the effects of considering variability in material properties; and to compare deterministic and probabilistic slope stability analyses results. Deterministic limit equilibrium, probabilistic limit equilibrium, and probabilistic finite element analyses are conducted for Lodalen landslide in Oslo, Norway and the results are compared with each other. The factor of safety, the probability of failure and the most critical failure surface are investigated with and without statistical cross-correlation of soil’s shear strength parameters. The results of this study can provide further insights into the comparison of deterministic and probabilistic approaches in slope safety.
Sakarya University Journal Of Science


Probabilistic Slope Stability Analyses Using Limit Equilibrium and Finite Element Methods
Akbas, Burak; Huvaj Sarıhan, Nejan (2015-10-16)
This paper compares the results of different probabilistic approaches and emphasizes the necessity of probabilistic analyses in slope stability studies. To do that, Limit Equilibrium Method (LEM) and Finite Element Method (FEM) are utilized and their outputs are compared in terms of probability of failure (PF), reliability index (RI), factor of safety (FS) and the failure surface. Lastly, concept of Random Finite Element Method (RFEM) is studied and effects of spatial correlation distance are investigated.
Probabilistic Slope Stability Analyses: Effects of the Coefficient of Variation and the Cross-Correlation of Shear Strength Parameters
Oğuz, Emir Ahmet; Yalçın, Yağızer ; Huvaj Sarıhan, Nejan (2017-03-15)
The assessment of the safety level of natural slopes, road cuts, embankments and levees require consideration of uncertainties and variability in material properties. In this study, for a number of slope geometries, including a real-life landslide case, probability of failure (PF) and the most critical failure surface are investigated with and without cross-correlation of shear strength properties. Slopes having different traditionally-defined factor of safety (FS) levels are studied. The uncertainty of soi...
Reliability analysis of a rock slope in Sumela monastery, Turkey, based on discrete element and response surface methods
Dadashzadeh, Neda; Düzgün, H. Şebnem; Department of Mining Engineering (2015)
It is widely recognized that a single factor of safety (FOS) calculated by traditional deterministic analysis methods may not represent slope safety due to involved uncertainties. The First Order Reliability Method (FORM) is one of the extensively used probabilistic methods in slope stability studies to quantify the uncertainties in the parameters. FORM can be easily applied when the slope is analyzed based on limit equilibrium methods. However, the recent numerical techniques are almost substituted by the ...
Affect of shear strength criteria selection in probabilistic rock slope stability analyses: A case study for a jointed rock slope in Norway
Düzgün, Hafize Şebnem; Bhasin, R. K. (2007-05-31)
Probabilistic rock slope stability analyses are essential to risk assessments, as risk is defined by the probability of occurrence of an instability multiplied by the consequences of the failure. Usually, probabilistic rock slope stability problems are modeled using the Coulomb failure criterion since it is linear, providing simple modeling algorithms. It is acknowledged widely that rock slope stability problems may exhibit non-linear failure behavior, leading to consideration of non-linear limit equilibriu...
Probabilistic slope stability analysis using limit equilibrium, finite element and random finite element methods
Akbaş, Burak; Huvaj Sarıhan, Nejan; Department of Civil Engineering (2015)
In recent years, geotechnical engineers are moving more towards decision-making processes based on reliability assessment, since accounting for soil variability and carrying out probabilistic analyses result in significant savings in designs, and possible prediction of failure events. Objectives of this study are to investigate and compare different methodologies for probabilistic slope stability analyses as well as with deterministic methodologies, in terms of factor of safety, the probability of failure, ...
Citation Formats
N. Huvaj Sarıhan, “Probabilistic Slope Stability Analysis: A Case Study,” Sakarya University Journal Of Science, pp. 1458–1465, 2018, Accessed: 00, 2020. [Online]. Available: