The effect of error in estimation of input parameters on predicting error of pavement life using Monte Carlo Simulation method

Pavement design using mechanistic-empirical methods is often carried out based on the some assumptions for pavement layer''s properties (thickness، elastic modulus، Poisson''s ratio and ….)، loading properties (axial weight، tire coordinates، number of repetitions and …) and also the failure mechanism for different materials. Fulfillment of these assumptions for evolution of pavement performance during service life is impossible. This is because of the uncertainty in the traffic preaiction of different vehicles،problem ofprecise determination of material specifications due to high cost of some tests and also errors and limitations in the construction phase. The error Existance in the estimation of input pavement design parameters leads to the probabilistic procedure. for the pavement design This helps the designer to study the influence of uncertainty of input parameters on the pavement performance parameters and finally controlling the design reliability. Because of the complicated computations for pavement analysis and its performance prediction، classical methods based on the deviation are not applicable to the reliability analysis of pavement performance. In this paper، the effect of the error in estimating the different input parameters of pavement design (elastic modulus، thickness and tire pressure) on prediction error of the fatigue and rutting life is studied using Monte Carlo Simulation method. For this purpose، three pavement sections with different structural capacity were considered and importance of each input parameter on prediction error of fatigue and rutting lifehave been prioritized. The possibility of using Monte Carlo simulation to develop some relationships to estimating the pavement rutting and fatigue life error has been explored. These relationships can be applied for future reliability analysis without using simulation