Abstract:The mechanical properties of the tailings provide important basic parameters for the design and stability evaluation of the tailings dam. The consolidated undrained tests were carried out to investigate mechanical properties of the coarse and fine tailings.The mechanical and deformation characteristics of coarse and fine tailings were obtained. The results indicate that the stress-strain relationship of coarse tailings included three stages: elasticity, plasticity and critical state. The peak strength and friction angle of coarse tailings is obviously larger than that of fine tailings. But, the cohesion of the coarse tailings is smaller than that in the fine tailings. The bulging deformation occurs in the coarse and fine samples. The magnitude of deformation in the coarse tailings is larger than that of fine tailings.