Under Repeated Loading, High Liquid Limit Clay Subgrade Permanent Deformation

High liquid limit clay was bad as subgrade filling which widely distributed, and the physical and mechanical property of high liquid limit clay was poor. In order to effectively use the high liquid limit clay and ensure the long-term mechanical properties, it's necessary for studying the deformation characteristics and the dynamic parameters of the clay under the dynamic loading by testing the high liquid limit clay and cement soil treatment in the laboratory.First, the tests of basic behaviors, resilience deformation, permanent deformation, dynamic strength were studied in laboratory. The regression equation of resilience deformation and permanent deformation were established by experimental method. The dynamic stress amplitude was given by the strain of 1% allowed.Second, engineering characteristics of high liquid limit clay cement stabilization were studied. The tests include compaction test, unconfined compression test, dynamic strain and dynamic strength, and so on. Compared with the High liquid limit clay, the dynamic strength of high liquid limit clay cement stabilization has a prominent increase. High liquid limit clay cement stabilization satisfies the condition of subgrade soil to highway.Finally, getted dynamic mechanical parameters by the tests and considered with filling conditions in field, the subgrade model was established by FLAC3D, which was consisted of high liquid limit clay(embankment part) and cement soil treatment(roadbed part), to compute the dynamic response of subgrade under the standard axle load. Verified the high liquid limit clay can't fill embankment fully, from the embankment surface below 1.2m range need improvement.