An insight into the creep mechanisms of a clayey soil through long-term consolidation tests

Creep or secondary consolidation of the clayey soil is critical and should be investigated. In this study, the creep behaviour of a clayey soil was investigated in the laboratory by conducting long-term oedometer tests. Standard loading and unloading procedures were followed to investigate creep for more than 1 year. The results confirmed the high creep potential of the clayey soil. Furthermore, the creep strain rate did not always increase with the load level because of the oedometric modulus hardening effect, which could be closely related to the rearrangement of the soil particles produced by secondary consolidation. A relationship existed between the compression index and the secondary consolidation coefficient, and their ratio was constant at approximately 0.026. The permeability approximately linearly increased with the void ratio. The difference in the creep behaviour at the same loading or unloading load levels indicated that the creep of the clayey soil was essentially stress-path dependent.