ABSTRACT
Conventional limit equilibrium and numerical modelling slope analysis techniques have distinct advantages and disadvantages inherent in their respective methodologies. The analysis technique chosen will depend on the site conditions and the potential mode of failure identified. The engineer must be aware of all existing slope analysis tools and be cognizant of their limitations. Knowledge of these different methods is essential in view of the potential variation in the input parameters required and in the subsequent interpretation of the generated results. In complex cases the required analysis methodology may not involve the use of a single technique, but may require the integrated use of several conventional and numerical methods. One such example is the 1991 Randa rockslide in the southern Swiss Alps, where failure occurred in two distinct episodes, involved several complex mechanisms relating to geological, mechanical and hydrological processes, and for which no clear triggering mechanism can be asserted.
