Investigation of embankment deformation mechanisms in permafrost regions

A numerical model including heat transfer, soil compression, thaw consolidation, and creep was established to analyze the embankment deformation in permafrost. The settlement behavior of an embankment along the Qinghai-Tibet Highway was simulated using Abaqus software. The settlement mechanism was analyzed based on the distribution of additional stress and settlement at different depths. It was found that (1) the embankment can be treated as an additional load on the underlying natural ground; the additional stress is mainly distributed underneath the embankment and has an effect up to 3 m depth; (2) the large amount of heat absorbed by the asphalt pavement created a thermal disturbance that caused permafrost degradation under the embankment, and a small stress can resulting in large settlement; (3) soil compression, thaw settlement, and permafrost creep all contributed to the total settlement. The permafrost degradation was the dominant process affecting the embankment deformation. Therefore, engineering measures should be considered to protect the permafrost underneath the embankment during the design process.