Newly Preventive Maintenance Techniques For Asphalt Pavement Based On The Lateral Re-distribution Of Traffic Loads

Since the1990’s, the highway construction has been undertaken at a high speed in China.However, there exist more and more problems in highway maintenance with the rapidincrease of the mileage, especially the greater technical gap in preventive maintenancetechniques with other countries. In China, asphalt pavement is adopted for most of theexpressways, and most of the preventive maintenance techniques for them are from othercountries. Therefore, it is of great significance to study and develop new techniques of ourown for the maintenance of the asphalt pavement of expressways.For a long time, the experts on pavement engineering have been studying the problemsof how to stop the pavement diseases and how to prolong the life-span of pavement. And theyhave mostly centered around the work for the improvement of asphalt pavement materials andthe pavement structures. The author in the present thesis believes that the action from trafficloads is the main cause. He proposes a new kind of maintenance technique from the angle oftraffic engineering and conducts in-depth study of the key techniques and applicationfeasibility on the theoretical basis.The thesis firstly studies the disease-producing mechanism of asphalt pavement andsummarizes the lateral distribution laws of pavement diseases, and then analyzes the restraintof channeling traffic for vehicle running. The author also sums up the lateral distribution lawsof vehicle axles and examines the uniformity of the lateral distribution from both pavementdisease and vehicle axles. On the basis of these, the author puts forward a new kind ofpreventive maintenance technique——lane marking-changing technique from the theory oflateral redistribution law of traffic loads, and carries out extensive analysis for the principlesto prolong the pavement life-span.The determination for the right time to change lane markings is one of the key techniquesof the new method. In the present study, the traditional method and the new technique arecombined, hence, the matching method is proposed. The author, in the consideration of theinfluence of rut depth on running, offers an analytical method for pavement rut depth.Through analysis for attenuation law of pavement marking performances and its influence ontraffic safety, the author uses periodic method of markings to explain when and how to change the markings.The lane marking-changing technique is also involved in the changing extent, changingsequences and changing frequencies. As rut forms may affect vehicle running and there existsmicro-mechanism for the formation of the unstable ruts, the study gives two determinationmethods for the marking-changing extent——pressure augmentation method and balancedload method with the principle of mechanical balance and peak load shifting. After theanalysis for the differences of wheel load under the conditions of arch pavement, the changingsequence is determined, and with the analysis for rut formation changes and markingreflection attenuation, the changing frequency is determined.In order to examine the recovery of asphalt pavement ruts after the adoption ofmarking-changing technique, the indoor tests were conducted, and BP neutral net was used tosimulate the recovery results of the technique on the basis of the test.The thesis, at last, analyzes the feasibility and practicability of the new technique fromthe pavement width and economic benefit. In consideration of the actual situation of China’sexpressway pavement width, the author studies the influence on vehicle running after thechanging of the markings, offers practical plans in doing the work, conducts economicfeasibility and stimulate the possible influence on vehicle running after the changing of thelane markings.