This paper presents an application of calculation scheme of slope stability reliability assessment published by Duncan and Wright in 2005. For the presentation of the calculation procedure, a case study of Warsaw Slope stability in the area adjacent to the rectory of St. Anne Church was analyzed. The shear strength reduction (SSR) technique, belonging to the FEM, was used for the calculation of geometrically spatial deformation state. On the basis of archival materials three sets of strength parameters (the lowest, medium and highst) were selected. Sets of strength parameters were used to safety factors (F) calculations. The results of F calculations were used to estimate the standard deviation and coefficient of variation. Subsequently using correlations made by Duncan and Wright, the probability of failure (Pf) and finally index of reliability (R) were determined. The analysis of stability using the Duncan and Wright method shows the possibility to take into consideration various safety factors, in relation to different strength parameters. Furthermore the used method enables quantitative comparison of various probably of landslide evaluations.

19-30