# Recent developments in landslide studies: probabilistic methods. State-of-the-art-report - Session VII (a)

#### Chowdhury, R.N.

#### IV International Symposium on Landslides, Sept. 16-21, 1984, Toronto, Canada (ISL 1984): 209-228

#### 1984

Considering the purpose and place of analysis in the study of slopes and landslides, it is fruitful to examine the recent trend towards probabilistic approaches. In this state-of-the-art paper basic definitions and methodology are reviewed and attention is then given to the modelling of soil variability within a probabilistic framework and its implications. Probabilistic approaches complement conventional deterministic studies and the advantages of these approaches are discussed in this paper. Reference is made to the methodology for predicting the most probable extent of failure of embankments and natural slopes, the modelling of slip surface propagation and progressive failure which is a consequence of the strain-softening nature of earth materials. The potential use of available techniques for predicting the likelihood of successive failure is discussed. Recent work on updating risk and reliability under static and seismic loads and on predicting failure due to rainfall is also reviewed. Different calculation techniques namely Monte Carlo simulation, Taylor series method and Rosenblueth method are compared. Finally attention is given to the role of probabalistic methods in decision making and to the limitations of probabilistic methods.