역학적 포장설계를 위한 등가하중계수 산정에 관한 기법개발

It is well known that vehicle`s speed, load, and size affect behavior of pavement. However existing methods to determine Equivalent Single Axle Load cannot consider the characteristics of moving vehicle. The purpose of this study is to reveal moving dynamic effects resulted from the vehicle speed using both the MDD(Multi Depth Deflectometer) tests and dynamic finite element analyses. For the purpose of that, Dukpyung section was selected as a test site. Under various vehicle speeds, the deflection of each layer were measured with the MDD. Influence depth was proposed from loading duration based on elastic wave theory. Using the influence depth and the maximum depth deflections, it is found that constant elastic modulus, regardless to vehicle speed, is acquired in the same place. Therefore, back-calculation process proposed in this study is verified to be very useful to reduce the difference of properties caused from change of vehicle speed.<BR> Based on the test results, using the vehicle speed as a parameter, regression analysis equations between the axle load rate and the deflection rate are proposed. Therefore, the proposed equations can be used at the test road to evaluate the moving vehicle load from the analysis of depth deflection. and the wheels of vehicle pass irregular route on a pavement, and the different positions of the wheel influence the behavior of pavement. for evaluation of asphalt concrete pavement behavior under various wheel position, ABAQUS, a three-dimensional dynamic finite element program (3D-DFEM), is used. 3D numerical model is verified from Multi - Depth Deflectometer (MDD) test results. According to various wheel position, the flexible pavement behavior with various elastic moduli is analyzed through numerical analysis. To evaluate the relations between wheel position and maximum deflection, maximum deflection reduction factor is developed through the regression analysis. It is shown that the maximum deflection can occur between wheels specially when the material properties of subbase and subgrade are decreased.