Impact of Aircraft Load on Additional Stress Depth in Soil Foundations Beneath Cement-concrete Pavements

To study the influence range of the soil foundation depth under the cement-concrete pavement of an airport under an aircraft load, a finite element model of the cement-concrete pavement—cement stabilized gravel base—soil foundation was established using FLAC3D finite element software, and the subprogram of the aircraft moving load was presented. The effects of the static and dynamic load of the aircraft on the pavement depth under different aircraft types, pavement thicknesses, and soil properties were compared and analyzed; the rationality of the numerical calculation was verified based on numerical examples. The results indicate that a heavier aircraft load requires more complex main landing gear, resulting in a greater influence range of the additional stress at the depth of the soil foundation caused by the aircraft dynamic load. A greater thickness of the cement-concrete pavement results in a lower additional stress in the soil foundation caused by the aircraft dynamic load, and the corresponding influence depth of the soil foundation gradually decreases. As the rebound modulus of the soil foundation increases, the additional stress in the soil foundation caused by the aircraft dynamic load increases, resulting in a greater influence of the additional stress on the soil foundation. The analysis also demonstrated that the additional stress depth in the soil foundation caused by the aircraft static load is greater than that caused by the aircraft dynamic load. In particular, the depth of the additional stress in the soil foundation caused by the static load of A380-800 aircraft σ c σ c σ 0 σ 0 = 0.1 exceeded 10 m. This study provided a quantitative reference for the optimization design of pavement structure parameters of different airport grades and the determination of the thickness of soil compaction treatment in the affected area of pavement foundation, which is conducive to the long-term safe operation of airports.