ABSTRACT
Soil and rock masses naturally present heterogeneity at various scales of description. This heterogeneity may be of two types. On a large scale, soil properties may be considered piece-wise homogeneous once regions (e.g., layers) have been identified. On a lower scale, the local spatial variability of the properties shall be accounted for. In any case, the use of deterministic values for representing the soil characteristics is poor, since it ignores the natural randomness of the medium. Alternatively, this randomness may be properly modeled using probabilistic models.
