Mechanistic analysis of frost heave in airport runway subgrades in seasonal frost regions and pavement structural tolerance thresholds

This study addresses the structural damage of airport pavements caused by uneven frost heave in seasonal frozen soil regions. A three-dimensional finite element model based on elastic layered system theory was established to simulate pavement mechanical responses under various frost heave parameters (heave magnitudes: 5-30 mm, wavelengths: 6-20 m). Key findings reveal that: (a)The bending tensile stress at slab bottom in frost valley areas significantly exceeds that in frost peak regions, with maximum stresses concentrated at frost valley boundaries (2.466 MPa at slab top) and centers (2.531 MPa at slab bottom) ;(b) Both frost heave magnitude and wavelength exhibit linear positive correlations with pavement stress, while void areas expand with increasing parameters. Through fatigue stress calculations and specification validation, frost heave control criteria were proposed: permissible heave magnitudes of 20 mm for airports with Flight Area Code Ⅱ A/B and 15 mm for Code Ⅱ C-F facilities. The research establishes quantitative guidelines for frost-resistant pavement design in cold regions, effectively mitigating structural damage risks and extending pavement service life. This work fills the gap in the mechanical analysis of frost heave in airport pavements, providing theoretical support for infrastructure durability optimization and aviation safety enhancement in seasonal frozen soil areas.