Research On Network Level Decision-making Of Highway Asphalt Pavement Maintenance Based On Matter-element Model

With the constant improvement of highway network,the expressway mileage has been bigger and bigger.Every highway pavement meets varying degrees of damage.But the annual maintenance budget is limited,which is difficult to meet the demand of all the highway maintenance.It is urgent and important to make a rational maintenance budget allocation to the network of highways in need of maintenance,so as to achieve maximum economic benefits and extension of pavement life with limited funds and under restricted pavement performance.In this paper,the study on the network level decision making problem of highway asphalt pavement was carried out,which is based on the research results of project level pavement maintenance management decision support system for the highways in Jiangsu Province.Network level pavement maintenance decision-making is a multi-factor and multi-objective problem.By investigating the overall condition of the highway network and expert consultation,a total of six pavement maintenance related indices were considered in the study,including pavement performance,pavement structure strength,pavement structure and material,traffic loads,pavement age and road grade.The six indices were normalized to the same scale of 0 to 100 for the matter-element analysis.Power,logarithm and cubic curves with high R square values,were employed to rescale the decision-making influence indices of pavement structure and material,traffic loads and pavement age.This paper proposes an Analytic Hierarchical Process(AHP)theory based method to determine the weight of the decision-making influence factors,considering their relative significance.The weightings of the six factors including pavement performance,pavement structure strength,pavement structure and material,traffic loads,pavement age and road grade were quantified through AHP method,which were WP=[0.5176,0.1840,0.1271,0.1020,0.0405,0.0287]T,From the aspect of maintenance cost,the sensitivity analysis results were in accordance with the weightings of different maintenance decision-making factors.The pavement maintenance cost was significantly sensitive to the change of pavement performance.After the quantification of evaluation indices,matter-element analysis was conducted to determine the comprehensive correlation degree,which indicates the overall ranking of a road section in the network level decision-making.This study took a deep investigation into the cost-effectiveness of typical pavement treatments used in Jiangsu,China.Rutting Depth was selected as the pavement performance indicator since it is more critical than roughness index.Pavement Distress Condition Index(PDCI)was also adopted as the comprehensive evaluation index to calculate the benefit of pavement maintenance.Compared with growth model,linear model,logarithm model,and exponential model,cubic model has higher R squares and significance level.Cubic model was selected to modify the performance development curve of Rutting Depth and Pavement Distress Condition Index.The life cycle cost analysis(LCCA)method was used to compare the cost of different treatments and the benefit over cost ratio was calculated to quantify treatment cost-effectiveness.Analyses results show that thin hot mix asphalt(HMA)overlays and micro surfacing are more cost-effective than Hot in-place recycling on light and moderate traffic roads.Hot in-place recycling and thick HMA overlays have much longer service lives and greater cost-effectiveness under heavy or extra heavy traffic.The commonly used prediction models have been compared,then prediction method of highway asphalt pavement performance has been determined.The gray prediction model was selected to simulate the pavement rutting development.Based on the pavement performance prediction results,decision tree was adopted for determining the road sections in need of maintenance in the project level decision-making process.The pavement maintenance treatment for each section could also be selected for the pavement maintenance requirement plan in the next few years.This paper proposes an optimization model based on the ranking results of road sections and dynamic programming for network level highway pavement maintenance decision-making.The optimization is to maximize the overall ratio of benefit over cost in the analysis period through the method of dynamic programming and the method of integer programming.The computing work could be greatly reduced based on the ranking results of road sections in need of maintenance.Moreover,the optimization result of pavement maintenance plan would be more reasonable and more credible.The decision-making optimization model with dynamic programming method could be successfully used for setting the pavement maintenance capital allocation plan in three years for the 14 highways in Jiangsu Province.The optimization model is reasonable and practical.This study can be used for establishing a reasonable network level highway pavement maintenance management system,and also provides a full range of technical support for the highway pavement maintenance and management.It has profound practical significance for highway maintenance and management in China.