Effect of fine particle content on mechanical properties of tailings under high confining pressure

The influence of dam height and fine grain content on the stability of the tailings dam is not a simple function. According to the layering rules of ultra-fine tailings in deep and large tailings ponds, four kinds of fine-grained (particle size less than 0.074 mm) tailings materials were prepared. Simulation of the physical and mechanical properties of ultra-fine tailings during the accumulation of high tailings dam was conducted. The optimal tailings mix ratio was determined through multi-physical index experiments and multi-evaluation index analysis. Multi-stage confining pressure triaxial shear failure test was conducted using TSZ-6A strain-controlled triaxial apparatus to recur the change law of mechanical properties of tailings based on large amounts of experimental data. Through high-precision laser particle size analysis and analysis of pore water pressure at full pressure, intrinsic influence factors and mechanism of physical and mechanical properties from the perspective particle fracture and pore water were analyzed. Finally, using elementary error theory, the method for evaluating Mohr strength parameter of tailings materials was modified, and the factor that caused confining pressure to change the structure of the material was taken into account.