Assessment of reliability-based design of stable slopes

Abstract

The viability of applying reliability-based design in the limit equilibrium evaluation of slope stability is assessed. Two model slopes are designed according to the limit states specification of European standard EN 1997:2004 and reliability assessed using full Monte Carlo calculation with 106 trials. Comparison of these results with reliability estimates obtained via a spectrum of different analysis techniques, broadly grouped into first-order reliability methods (FORM) and performance function moment estimation methods, indicates that FORM-based techniques are superior, with a first-order response surface method found to provide the best combination of accuracy, stability, and speed of convergence. In this way, accurate reliability indices for nonclosed form problems of the nature considered here can be obtained within 20–30 function calls, depending on the number of free parameters and required precision.