Uncertainty about p‐y Curves for Piles in Soft Clays

Abstract

Criteria for estimating the first two probabilistic moments of the normalized parameters of $p‐y$ curves are presented. These parameters are the ultimate soil resistance and the initial tangent value of the soil reaction which are both normalized with respect to the values predicted by an adequate mathematical expression. Due to the scarcity of data a sequential Bayesian formulation of statistical inference is adopted which deals with engineering judgment; small scale models of piles under lateral loads, as well as full scale specimens and indirect information is contained in load‐deflection curves measured at the heads of laterally loaded piles. When assessing the possible deviations of the normalized variables, attention is given to: uncertainty attached to the prediction formula of the $p‐y$ curves; influence of uncertainty in basic soil properties; and discrepancies among results from small scale models and field tests. Mean and variance values of the normalized parameters of $p‐y$ curves corresponding to soft and medium saturated clays are obtained for a particular case.