Using large-scale shearing device

consolidation-drained triaxial test and isotropic consolidation-drained triaxial test under different confining pressures are performed for three relative densities (0.9

0.8

0.7) overburden material of ShuangJiangKou earth dam. The difference between dilatancy behaviours of coarse-grained soil under -consolidation and isotropic consolidation is investigated. Meanwhile

applicability of the modified Rowe dilatancy equation for coarse-grained soils under -consolidation is tested. The test results show that the dilatancy under -consolidation is more remarkable than that under isotropic consolidation; and this difference is more obvious for coarse-grained soils with lower density. By means of the nonlinear fitting of the results of triaxial tests

a relationship formula for coarse-grained soils under -consolidation and isotropic consolidation among dilatancy factor and relative density and confining pressure is obtained

according to which

the dilatancy’ strength of coarse-grained soil under different consolidations can be judged. For the coarse-grained materials under -consolidation

of which dilatancy characteristics can be reflected well by the modified Rowe dilatancy equation.