Optimum Design of Flexible Pavements in the Presence of Uncertainty Using Subset Simulation: Fid-Bau Portal

Optimum Design of Flexible Pavements in the Presence of Uncertainty Using Subset Simulation

Dilip, Deepthi M.

This study presents a framework for the quantification of parameter uncertainties that influence the design life of flexible pavements, with a focus on the optimum design to safeguard the structure against fatigue and rutting. A challenging issue for probabilistic analysis of pavements is the intensive computational demand for estimating pavement responses under loading using finite element models. In this study, the subset simulation (SS) methodology is used to compute the failure probability in a much shorter time. However, this technique is not appealing from a practitioner’s viewpoint as it does not yield the design point or sensitivity indices. By combining it with polynomial chaos equations (PCE) based meta-models to formulate the failure surfaces, the design point was estimated through a simple constrained optimization problem. The Sobol sensitivity indices obtained from the PCE coefficients indicate that the base layer modulus is the most significant parameter contributing to fatigue failure followed by the surface layer modulus. These results are corroborated by the sensitivity plots obtained from Subset Simulation and are consistent with findings from other studies.