Abstract
To study the statistics of the settlement of pile foundations, the uncertainty in the Young's modulus of the soil must first be estimated. This paper considers the practical aspects of estimating the uncertainty in the model for quantifying the Young"s modulus of the soil as well as the uncertainty due to the inherent variability of the basic soil property, namely, the shear strength. The uncertainty in the model is evaluated by treating the correlation parameter as a random variable; the soil is modeled as a spatially random medium. Through a numerical example it is shown how these two uncertainties can be simultaneously considered in evaluating the reliability of the pile foundation against an allowable settlement limit using design charts. The design charts were formulated based on first-order computations and validated in this paper by comparing with second-order results over the range of values of practical interest.