Abstract:In order to study the shear strength of different plastic subgrade soil subjected to freeze-thaw cycles, three kinds of plastic indexes of soil samples are studied through the laboratory triaxial test and freeze-thaw cycle test. The results show that when the number of freeze-thaw cycles increases, the shear strength increases with the increase of plastic indexes. When the plasticity index is the same, the shear strength changes differently with the increase of freeze-thaw cycles and confining pressure, in which the shear strength is inversely proportional to the times of freeze-thaw cycle and directly proportional to the confining pressure. After 6~7 times of freeze-thaw cycles, the changes of shear strength of the three kinds of plastic index soil samples tend to be gentle.
