Structural Reliability Evaluation Method Of Asphalt Pavement

Survey shows that the uncertainties in the road engineering have a great impact on the performance of the pavement structure.Therefore,the research on the reliability of the pavement has been carried out,the characteristics of the pavement design parameters have been analyzed statistically.Considering the stochastic characteristics and variability of the design parameters in road engineering process,the concept of reliability is introduced to form a set of more reliable reliability theory.However,due to the complexity of the reliability theory itself,the existing reliability evaluation method of pavement structure is difficult applied to engineering practice.Therefore,based on the analysis of 19 kinds of pavement structure data in the full-scale loop structure field provided by the Ministry of Transportation,the paper introduces the error transmission formula to calculate the reliability of the pavement structure,and the pavement design structure and the road surface obtained from the measured data The reliability of the actual structure is analyzed and evaluated,and the reliability of the multi-index system is analyzed synthetically.The relationship between the multi-index is established by using the response surface equation.Finally,the reliability index of the system is evaluated to evaluate the comprehensive reliability of the pavement structure,At the same time,this paper analyzes the different pavement structures with this index,and gives the pavement structure with better reliability.The main research contents are as follows:Firstly,the variation range and probability distribution form of the foundation parameters of the pavement are analyzed.The basic parameters and their variability are substituted into the calculation of the reliability of the design pavement structure for the calculation of the structural reliability.The error transmission formula is introduced into the coefficient of variation And the variance is calculated to obtain the reliability of the pavement design structure with the deflection and the bottom tensile stress as the evaluation index respectively.Considering the accuracy of the new algorithm,ANSYS finite element analysis algorithm is used to analyze the reliability,including its reliability results and verification of the sensitivity of each parameter.Secondly,according to the existing measured data,the reliability analysis of the actual structure of the pavement is carried out.After obtaining the reliability of the mechanical performance as the evaluation index,the engineering quality index includes three large volume indexes(porosity,slag gap,asphalt saturation)On the reliability of pavement structure,and obtain the reliability of pavement structure under the volume index as the evaluation index.Finally,the relationship between the engineering quality index and the mechanical performance index is established by introducing the response surface equation.At the same time,the corresponding evaluation system is established to analyze the reliability of each index,and the reliability of the system is taken as the evaluation index of the overall structural reliability of the pavement,The design structure and the actual structure are evaluated separately to determine whether the actual pavement structure is relatively reliable for the design of the pavement structure.At the same time,the reliability of the pavement structure is compared and analyzed,and the quality of the structural reliability and the quality of the construction are judged.