Experimental study of mechanical behavior of a coarse-grained material under various stress paths

A series of large-scale triaxial tests under different stress paths are performed, including the conventional triaxial tests, constant p tests and constant stress ratio tests. Based on the comparison of test results, the stress-strain, deformation and strength characteristics of a coarse-grained material under different stress paths are investigated. Meanwhile, the phenomena of the volume-contraction in unloading is discussed. The test results indicate that the stress path has obvious influence on the stress-strain and deformation characteristics of the coarse-grained material, but little influence on strength characteristics. The volume-contraction in unloading of the coarse-grained material is caused by the change of deviatoric stress ratio and is related to stress path of test.