Abstract: Dispersive clay is a kind of soil with special engineering properties, and with typical features of poor impermeability, low erosion resistance ability, very high dispersiveness when it is in pure water. In recent years, the study of dispersive clay in the field mainly focuses on identification, penetrability, betterment and other aspects; however, the studies of shear strength properties are rare. In this paper, the conventional triaxial compression consolidated undrained (CU) test is adopted to study the dispersive clay’s shear strength characteristics under different initial conditions. The results show that: dispersive clay’s stress-strain curves present the softening type when it is under the conditions of small confining pressure, low moisture content and high dry density; but it changes into the weak hardening type or hardening type when it is under the conditions of large confining pressure and high moisture content. Dispersive clay’s cohesion and internal frictional angle all decrease while the moisture content increases. In addition, the higher the dry density is, the stronger influence of moisture has on the clay’s cohesion and internal frictional angle; its cohesion increases with the increase of dry density; and it has a larger increment under the low moisture content condition compared to that under the high moisture content conditions; internal frictional angle has a small increment with the increasing of dry density.

Key words: dispersive clay, shear strength, moisture content, dry density