Research On The Dynamic Synthetic Deflection Correction Coefficient Of Asphalt Pavement

When structural response analysis is carried out under the existing asphalt pavement structure design method, material parameters cannot truthfully reflect the mechanical properties of soil and material, and deflection index cannot reflect the diversity of pavement structure and damage types. In order to improve the design method and index of the asphalt pavement, Research on Asphalt Pavement Design Indicators and Parameters is developed by Ministry Of Transportation And Communications, then dynamic parameter design method under a new system is established, however, the corresponding quality inspection is lacked. Because of the difference between theoretical and measured deflection, deflection correction is needed, in this paper, the asphalt pavement dynamic deflection comprehensive correction coefficient is studied.Main factors which lead to the difference between theoretical and measured deflection are obtained through this analysis, thet are climate (temperature, humidity) and material parameters, when the influence of climate to deflection is eliminated, the nonlinear of soil and modulus selecting of other structural layers become the main factors.Indoor full-scale and outdoor test road is constructed, then material and structure parameters are gathered, and FWD, Benkelman Beam and bearing plate test are carried on. By analyzing the deflection data obtained, the temperature correction formula of the FWD center deflection is established, K = e?0 .116( T ?20)h, so the measured deflection of the different temperatures can be corrected to the standard deflection at 20℃. ABAQUS is used to calculate theoretical deflection with subgrade nonlinear constitutive model and dynamic parameters of the other layers.F value of the different structure in test road is calculated, according to the definition of synthetic deflection correction coefficient. By analyzing standard F correction formula and the results of this research, the variable in correction formula can be fixed, and through sensitivity analysis of deflection basin,the corresponding parameters can be selected to create a new F modified formula , F =0.34AREA0.361d1800.276S40.201.