Probabilistic hyperbolic models for foundation uplift movements

Abstract

There is a need to consider both ultimate limit state and serviceability limit state uniformly within the reliability-based design framework. However, it is more difficult to characterize uncertainties associated with the latter, because load-displacement curves are nonlinear functions that cannot be reduced to a single random variable. This paper demonstrates that a random vector containing two curve-fitting hyperbolic parameters is an adequate probabilistic model for uplift load-displacement curves associated with spread foundations, drilled shafts, and pressure-injected footings. A simple but general computational approach, based on Hermite polynomials, can be used to simulate these hyperbolic parameters, which typically are correlated and may not follow closed-form classical distributions. Copyright ASCE 2007.