The Study On Maintenance Decisions Of Expressway Network Asphalt Pavement Performance For Gansu Province

With the improvement of the highway network construction in Gansu Province,the total mileage of highways continues to increase,the road surface is damaged,and the annual maintenance investment is limited.Therefore,it is difficult to meet the maintenance needs of all highways.In order to ensure the service level of highways.At the same time,to ensure that the usability of the expressway meets the requirements of the "Thirteenth Five-Year Plan",how to allocate a expressway maintenance fund to the sections of the road network most in need of treatment is a problem that the expressway management department need to solve urgently.In this paper,the road network composed of 15 highway pavements in Gansu Province is used as a research project to study the decision-making problem of asphalt pavements of network-level highways.Firstly,the highway network of Gansu Province faces problems such as complex environment,ages,levels of maintenance,and huge performance data,highway sections need to be divided.In the division of conservation areas,the climatic natural areas,age,and vehicle flow of Gansu Province were selected as the indicators of division.The K-means cluster analysis method is used to divide the 15 highway into four regions.The types of road sections included in Types I and II are mostly more than 10 years old.Type I is light traffic and located in a natural area.Most of them are in areas with large day and night temperature differences or heavy rainfall,while the road sections in area II are heavy traffic,and most of them are in areas with low average annual temperature,large day and night temperature differences,and less precipitation.The included road sections are less than 10 years old.Type III belongs to lightmedium traffic.The annual average temperature is low,and there is less precipitation.Type IV is heavy traffic,with strong solar radiation,large temperature difference between day and night,and rare precipitation.The method can be used to classify the road sections with the same road condition characteristics into one class,and there is a large difference between classes.Secondly,the standing weight comprehensive evaluation method has a higher judgment level and the comprehensive evaluation standard is a standard determined for the pavement use status,it provides clear road condition information for the maintenance unit,and the standard used for pavement maintenance is not very suitable.Based on the variable weight-extension comprehensive evaluation method of expressway asphalt pavement evaluation model,this paper determines the weight of the pavement condition evaluation index based on the actual detection data,and establishes a mathematical model that is more in line with the actual condition of the pavement.Through the analysis of specific examples and comparison with the evaluation results obtained by the normative weighting method,it is verified that the results of the pavement condition evaluation model constructed in this paper can better reflect the pavement performance and provide strong data support for maintenance decision-making in the later pavement system.Combined with the road condition information of Gansu Province in recent years,considering the regional climate factors and maintenance levels of each highway are quite different,taking the road segments within the divided four pavement areas as the unit,through screening analysis of 15 highways in Gansu Province 2015-2018 Based on the annual pavement performance index data,a grey prediction model for pavement performance was established for the four sections of the expressway in Gansu Province.Comparing and verifying the 2019 pavement inspection data with the prediction results,the accuracy of the four indicators can reach more than 89%,and the prediction results are more reliable,which can effectively predict the attenuation law of asphalt pavement performance.The decision tree method was used to judge the two-stage maintenance countermeasures of the highway pavement in Gansu Province,and the comprehensive performance evaluation of variable weight and extension pavement was used to verify whether the choice of maintenance countermeasures is of reference.When the evaluation result is "excellent" or "Good",the road surface should be repaired;when the evaluation result is "good",the road surface should be repaired functionally or preventively;when the evaluation result is "medium" or below,the road surface should be repaired.Finally,the 0-1 integer algorithm is used to optimize the maintenance countermeasures.In recent years,the maintenance funds invested in maintenance projects in Gansu Province are used as the objective function to optimize the preventive maintenance road sections.Based on the grey model,the comprehensive ranking of the road sections in each of the four types of areas needs to be obtained.In practical applications,the construction of maintenance decisions cannot be met due to insufficient maintenance funds.Applying the sorting results to the optimization analysis process of the road network maintenance plan and maintaining the pavement according to the order of arrangement can greatly reduce the amount of calculation.The research results can lay the foundation for establishing a reasonable network-level highway pavement maintenance management system and provide technical support for China's future highway pavement maintenance management.