Simplified Probabilistic Slope Stability Design Charts for Cohesive and c-ϕ Soils

August 14, 2014

Recently, SVSLOPE® was used to develop a series of design charts for simple slopes combining quantitative estimates of the conventional factor of safety with matching estimates of the probability of failure considering random values of cohesive and frictional shear strength components having lognormal distributions. Two series of design charts were developed.

Monte Carlo simulations were run utilizing the conventional Simplified Bishop’s Method of analysis coupled with the probabilistic circular slip slope stability analysis option in SVSLOPE®. The results were used by the researchers to develop design charts for cohesive and cohesive-frictional soil slopes. Design chart accuracy was confirmed by comparing chart values with closed-form solutions where available, and results from other software packages. The charts may be used by geotechnical engineers to make preliminary estimates of the probability of failure of simple slopes without the need of first running Monte Carlo simulations.

The analysis required the utilization of SVSLOPE® for many thousands of model runs with a wide range of model input values. The analysis results compared closely to the results from other software packages. The successful completion of this research project demonstrates the stability and accuracy of the SVSLOPE® software package.

A recent journal paper that describes this work and presents the probabilistic slope stability design charts can be found at:

We have used SVSLOPE® for a research program at the Royal Military College to develop simplified probabilistic slope stability design charts. The software performance has been excellent and our few questions related to it's use were answered promptly by the staff at SoilVision Systems Ltd. I would recommend this software for use in the geotechnical consulting community as it is stable, robust, and compares well to similar software based on our study results.

Dr. Richard Bathurst, Ph.D., FCAE, FEIC, P.Eng.
Professor of Civil Engineering (RMC and Queen’s University)
GeoEngineering Centre at Queen’s-RMC Royal Military College of Canada

If you are interested in this type of analysis, the SVSlope® software package is available. Please visit our ordering page for pricing and purchase information, or contact us directly.