Incorporating uncertainties in flexible pavement design Available to Purchase

This paper presents a reliability-based design approach for flexible pavements against fatigue cracking. The approach involves the uncertainties in the design variables. Fatigue cracking models as functions of a set of input design random variables have been developed using the response surface method and mechanistic empirical pavement design (MEPD). The uncertainty in the input variables has been modelled with probability distributions. Non-linear limit state functions have been developed using response models and central composite design. The first-order reliability method has been used with the limit state functions to determine reliability against each failure mode and system reliability. The predicted fatigue cracking values were obtained for different reliability levels and hot-mix asphalt thicknesses. The design charts and tables developed in the study can be used to determine the thickness of an asphalt concrete layer using MEPD and system reliability. The use of the charts and tables in flexible pavement design has been presented by way of practical examples. The study demonstrates a methodology for incorporating uncertainties in the input variables in flexible pavement design with MEPD.