Study on mechanical and crushing characteristics of tailings in large-scale high tailings dam

Abstract The mechanical and crushing characteristics of tailings under high pressure are the research foundation for large-scale high tailings dams. In consider of the high stress caused by the high tailing pond, consolidated drained (CD) triaxial shear tests were carried out. A new method for qualitatively characterizing particle crushing by identifying particles was proposed. The relative broken index proposed by Einav was used to quantitatively characterize the particle crushing of tailings. The test results show that the samples density has a great influence on the volumetric strain under low pressure. However, volumetric strain is not related to the sample density under high pressure. The shear strength of the tailings shows a significantly nonlinear. The internal friction angle under low pressure be still obtained by the traditional linear Mohr-Coulomb, and the internal friction angle under high pressure be obtained by the power function Mohr criterion. The particle crushing of tailings not only occurs at high pressure but also at low pressure. The value of broken index increases with the increase of sample density and confining pressure. It indicates that the high density and high stress in the deep part of the tailings dam is prone to the particle crushing, which affects the stability of the large-scale high dam.