Rutting Behavior of Flexible Pavement in Airport Turning Area under Temperature Field

Since the lateral shearing effect of aircraft wheels during low-speed turning may aggravate the rutting defects of flexible pavement and jeopardize the driving safety, a numerical analysis model of flexible pavement structure coupled with a continuous alternating temperature field was established on the ABAQUS platform. In this model, the low speed turning performance of aircraft wheel on the ground was formulated and analyzed, and the laws of rutting formation in straight-line and turning areas of flexible pavement were compared. According to the deformation characteristics of pavement in turning area, a new evaluation index of rutting depth was proposed, whereby parametrical influences of traffic load and meteorological conditions on the rutting formation were analyzed. The results indicate that the transverse thrust of aircraft wheel load will lead to a notable lateral tensile deformation at the bottom of the pavement surface layer. The vertical stress at the loading position in the turning area is smaller than in the straight line area, which is in good accordance with the distribution of rutting depth. As the upheaval deformation at the external side of the outside wheel increases in the turning area, the upheaval deformation at the internal side of the inside wheel decreases and merges with the settlement basin together. The deformation can be reflected by the index of composite rutting depth and it presents a tendency to increase with the aircraft's turning speed, with a maximum amplification of nearly 50%. With the turning speed increasing, the accumulative action time of wheel load shortens, and the rutting depth at wheel marks decreases with a maximum amplitude of 30%. In addition, the continuous high temperature of surface layer of flexible pavement during daytime is a vital environmental reason for the rapid development of rutting formation in the initial stage. The sensitive temperature of rutting formation in the flexible pavement under study is around 30℃. The rutting deformation of the turning area can be remarkably reduced by limiting the minimum taxiing speed in high temperature conditions.