Study On Rutting Development Rule Of Jiqing Expressway Asphalt Pavement After Maintenance

Most freeways built early in our country are mostly coming into overhaul period. As the first freeway built in Shandong province, Jiqing Freeway is still under preferable situation. It delegates the semi-rigid pavement in damage styles and maintenance management. Compared with crack and water damage, rut does the most serious harm to the pavement, which has become into the most important damage in asphaltic pavement. Much inside experiment and calculation has been done to modify the actual stress with rut, but it is different from the changing rules of rut under natural condition. Little has been done to study the changing rules after rut's maintenance considering the actual operation of the road. So it is necessary to study the changing rules and mechanism of rut after maintenance of freeway.Rely on the maintenance of Jiqing Freeway, this paper analyses systematically the pavement structure, the material type, the maintenance course and maintenance style, the checking data of the road, the traffic, the climate etc. It summarizes the experience of the maintenance and puts forward new token measure of the maintenance work. It analyses the damage styles, the damage course and the major factors, then it points out that shear is the main cause of rut, good material and gradation can minish the rut, stiffer asphalt or modified asphalt can advance the rut. The paper analyses the traffic, the vehicle style, the axis style and overload, and gains the traffic constitution and load conversion coefficient of every section on the road, both uplink and downlink.Analyzing calculation is done to the efficient traffic, educing the efficient axis number. Based on statistic measure, the paper has studied the effect by various factors, analyzed the cause and maintenance measure of rut, and found the changing principle after repair. Referring to the traffic load, temperature, structure parameter and creeping parameter, using ABAQUS finite element software, the paper simulates the developing mechanism of rut, and finds the calculated rut depth meets the practical rut depth well, so it builds a estimating model in advance, and gains the connection between the thickness of asphaltic surface and rut depth with different traffic times.Based on the study above, the paper puts forward the maintenance measure of rut as well as the reasonable milling layer, which can provide academic thereunder for the maintenance in Jiqing Freeway.