Effects of variability in thickness and elastic modulus on the reliability of flexible pavement structural performance

ABSTRACT

This study investigates the effect of variability of layer thickness and elastic modulus of pavement materials on the reliability of flexible pavement structural performance with respect to rutting failure using the mechanistic design approach. Monte Carlo simulation was applied to incorporate the variability of input design parameters in establishing the probability distribution of reliability of multi-layered flexible pavements. Using Matlab 7.0 programming language, a programme named DTC1.0 was developed for calculating the overall elastic modulus and pavement reliability. Data from some National Highways of Vietnam were used to construct statistical distributions of layer thicknesses and elastic moduli. Sensitivity analyses were conducted to identify key input parameters that have the most effect on reliability. The research shows that changing the value of the coefficient of variation (COV) affects the reliability of the flexible pavement at different levels: the higher the COV, the higher the rate of decrease in the reliability. Changes in thickness and elastic modulus of upper layers have more impact on reliability than lower layers. The influence of COVs of the elastic modulus is larger than that of the thickness. It is expected that the study can provide the foundation to develop a reliability-based design procedure following the mechanistic design approach.

KEYWORDS:

• Variability
• reliability
• elastic modulus
• thickness
• structural performance

Acknowledgements

The authors appreciate the Directorate for Roads of Vietnam for the provision of the data used in this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).