Effect of Spatial Variability in Asphalt Layer on Critical Pavement Response

Spatial variability of the soil or structural materials has been proven to induce harmful and non-negligible effects on the structural response in geotechnical engineering. Whereas only limited studies have incorporated spatial variability into the probabilistic analysis of pavement engineering as opposed to many other geotechnical areas. This study aims to assess the impact of spatial variability of Young's modulus of the asphalt layer on the critical pavement strain by using the random finite difference method (RFDM). The scale of fluctuation (SOF), as a key influencer, and the role of weak subgrade in the statistical effect caused by asphalt spatial variability is especially focused on by conducting a parametric study. Several conclusions are drawn. (a) The spatial variability in the asphalt layer can have adverse effects on the pavement response by increasing the mean value and inducing considerable variability (in terms of coefficient of variation). (b) A value of SOF is found to have the most unfavourable statistical effect on the critical strain. (c) The presence of a weak subgrade can aggravate the adverse effect of spatially variability.

Keywords: pavement, spatial variability, Random finite difference method, scale of fluctuation, Young's Modulus.