Adaptability of asphalt pavement structures to deformation of embankment underlain by black cotton soil

Three pavement structures, including fatigue-resistant layer sandwich structure (FRLSS), sandwich asphalt pavement structure (SAPS) and semi-rigid base pavement structure (SRBPS), were designed to investigate their adaptability to the differential deformation of highway embankment on black cotton soil (BCS), which shrink/swell behavior was modeled by the coupled consolidation theory for unsaturated soils. The maximum additional tensile stress in pavement was obtained, and the present serviceability index (PSI) and the international roughness index (IRI) were calculated by the vertical movement, pavement properties and traffic data. The adaptability of those pavement structures to the differential deformation of highway embankment was evaluated by grey relational analytical method using the PSI, IRI and additional tensile stress as the indexes. The results reveal that FRLSS presents the better effect in controlling cracks on the key-layer bottom, while SRBPS presents the better effect in controlling cracks on the pavement surface. The effect in controlling roughness decreases gradually from FRLSS, SAPS to SRBPS in order. The adaptability of FRLSS to the soil movement of highway embankment on BCS is superior to SAPS, which excels SRBPS. Overall, FRLSS should be given priority in designing asphalt pavement underlain by BCS foundation from the perspective of controlling roughness and cracks.