Investigation On Medium And Long Term Maintenance Planning And Application Of Normalized Preventive Maintenance For County And Township Roads Network

By the end of 2018,the total length of China's highways had reached 4,859,500 kilometers,and the mileage of highways exceeded 140,000 kilometers.The total mileage of county roads in rural areas has exceeded 4 million kilometers.At present,the road maintenance of rural and township road network is characterized by limited funds,low utilization rate of maintenance funds,unreasonable management mode,and separation of maintenance and decision-making.The paper aims to establish a reasonable medium-and long-term maintenance plan for the county and township road network by introducing the “normalized preventive maintenance” conservation model,which provide a reference to solve the outstanding problems existing in the management and maintenance of county road network and to guide the formulation of maintenance plan for County Road network.That the paper refers the decision-making process of highway pavement maintenance management to establish the decision-making framework for midium and long-term maintenance planning of county and township roads network,including road segmentation,road performance evaluation,road performance prediction,maintenance demand determination,and maintenance plan decision.Firstly,the dynamic segmentation method based on the basic attributes of the road surface is used to divide the road segments to determine the basic decision-making unit.Secondly,the threshold model for screening the error data is established,and the road and county road condition evaluation index system is established,and the cosine cosine weight is used.The method optimizes and analyzes the normative weights of the sub-item evaluation indicators,and calculates the road condition through the processed road condition data and the optimized sub-index weights to calculate the comprehensive evaluation index PQI.then,through the GM(1,1)grey prediction model is used to predict the road performance of each section of the road network.Determining the performance combination status of the road network during the maintenance planning period based on the road condition evaluation result and the road condition prediction result.The combination state is simplified,the established decision tree model is used to determine the road network maintenance demand during the maintenance planning period.and the “weighted deviation square sum difference comparison method” is used to prioritize the county road network maintenance priority.Finally,the normalized maintenance mode of preventive maintenance is introduced into the maintance program.With the 0-1 knapsack problem model as the prototype,the maintenance allocation model of maintenance funds was established,and the improvement and appreciation of the comprehensive pavement quality index(PQI)is taken as the benefit index.LINGO software is used to solve the core algorithm of the model,and the overall planning and long-term maintenance results of the county road network are obtained.Taking the five-year plan for maintenance and repair of network-level pavement of county and township roads in XX District of A city(2016-2020)as an example,the paper investigates the medium and long-term maintenance planning method of network-level pavement,so as to formulate maintenance planning decision-making schedules.on the meanwhile,the paper introduces the maintenance mode of " Normalized preventive maintenance " into the program.In order to maximize the benefit of limited maintenance and maintenance funds utilization,avoid the separation of maintenance demand and decision-making,and improve maintenance funds service efficiency of gold.Medium and long-term pavement planning and its methods can provide a reference for the formulation of maintenance planning of county road network.It is of great significance to improve the management level of county township maintenance.