STUDY ON THE FROST HEAVE DAMAGE MECHANISM AND PERFORMANCE DEGRADATION OF CONCRETE COMPONENTS IN SLAB TRACK STRUCTURES IN COLD REGIONS

This study investigates the frost heave-induced damage mechanism and performance degradation of concrete components in CRTS I slab track systems in cold regions. A 3D finite element model was developed based on plastic damage mechanics theory and the GB50010-2010 Code for Design of Concrete Structures, systematically analyzing the effects of frost heave wavelength, amplitude, and location on damage evolution in the base plate and track slab. Key findings include: (1) Damage sequence discrepancy: The base plate enters a significant damage stage (damage factor = 0.25) at 8.5 mm frost heave amplitude, whereas the track slab exhibits abrupt damage (damage factor = 0.819) only at 13 mm, highlighting the base plates higher susceptibility due to lower strength. (2) Failure mode contrast: The base plate shows compressive softening (post-peak stress drop), while the track slab demonstrates tensile ductility with sustained high residual stress post cracking. (3) Frost heave parameter effects: Shorter wavelengths(10 m) and higher amplitudes (>8 mm) exacerbate damage. When the frost heave peak shifts from the base plate center to the track slab center,damage energy increasesby18% 20.5%. The results provide theoretical support for optimizing CRTS I track design and maintenance, recommending prioritized base plate crushing prevention (8 mm amplitude) and long-term monitoring of track slab tensile cracks (13 mm).