Dynamic response analysis of airport pavements during aircraft taxiing for evaluating pavement bearing capacity

摘要

In this paper, we propose a new method to analyze airport pavement bearing capacity using vibration in runways during aircraft taxiing. The new method overcomes shortcomings of existing tests, such as flight suspension and simulated loading. Between aircraft take-off and landing, acceleration sensors are arranged on the surface of the pavement far from the centerline, and the in-situ responses of the pavement under aircraft loads are collected during aircraft operations. The fundamental frequencies of the pavement are obtained by fast Fourier transformation of the measured accelerations, and are used to modify the parameters of a pavement finite element model built according to a design blueprint. By comparing the fundamental frequencies of the measured and calculated signals, the soil modulus is back-calculated. To implement this test method and ensure the accuracy of bearing capacity evaluation, aircraft dynamic loads are obtained by solving dynamic balance equations of the aircraft-pavement coupled system, and the vibration response of the pavement and sensitivity analysis of the fundamental frequencies are introduced. The results show that the fundamental frequencies at the center of the pavement are basically the same as those at the far side on the cross section; the fundamental frequencies in the depth direction remain constant, but the amplitude of the frequency spectrum decreases. The effect of the soil resilient modulus on the vibration frequency is most significant. The fundamental frequency increases from 6.02 to 10.55 Hz when the soil dynamic resilient modulus changes from 91 to 303 MPa. The effects of surface thickness and base thickness on the vibration frequency are less significant, and there is minimal influence when changing the dynamic elastic moduli of the surface layer or base layer. Field test results indicate the efficacy of the method of vibration measurement at the pavement surface to estimate the layer modulus of airport pavement.