Surface deflection-based reliability analysis of asphalt pavement design

The surface deflection of asphalt pavement reflects the strength and stiffness of the entire structure, which can be used to evaluate the rutting life of asphalt pavements. However, it is influenced by various stochastic variables including traffic loads, material properties and structural thickness of each pavement course. The uncertainty of above stochastic variables is of significance for accurately predicting the rutting life of asphalt pavement. In this study, the statistical characteristics of stochastic variables of asphalt pavement were assessed based on the field data collected from asphalt pavement projects. A unique formula with a fairly good accuracy was found using multiple linear regression based on numerical simulation results to ease the calculation of pavement deflection during the reliability analysis. It is shown that the stochastic variables of asphalt pavement can be well characterized by normal distribution or logarithmic normal distribution. The regressed formula to calculate the surface deflection of pavement has a fairly good accuracy with an error of less than 6.0% compared to the numerical method. The proposed surface deflection-based reliability analysis can be used easily to evaluate the influence of input parameters on the rutting life and to guide the structure design of asphalt pavement with required reliability.