Study On Mechanical Properties And Statistical Damage Model Of Tailings Sanfd Under The Action Of Drying-wetting Cycles

In the course of China's modernization,mineral resources are important of socio-economic development,accompanying this is the increasing demand for mineral resources.However,more and more slags are generated during the development process.Tailings are generally stored in tailings ponds.Because of the special construction of the tailings pond,it will be affected by natural weather such as rainfall,frost and snow,so that it will be in a repeated wet and dry cycle environment.This effect will change the mechanical properties of the tailings material and will directly affect the safe and stable operation of the tailings pond.Therefore,this paper studies the mechanical properties of tailings materials by means of field surveys,triaxial shear tests,and construction of statistical damage models.The following research results are obtained:(1)Through laboratory triaxial shear tests,three factors affecting the shear resistance of tailings materials:dry density,moisture content,and the number of drying-wetting cycles are experimentally studied.Finally,the influence of these factors on the shear resistance of tailing materials is obtained.(2)It is found that the stress-strain curve,the effective cohesion and the internal friction angle of the tailing material change significantly with the increase of the number of drying-wetting cycles.(3)It is found that the shear strength of tailings is changed due to the effect of drying-wetting cycles,and after the number increases to a certain value,the shear strength of tailings gradually stabilizes to a certain range and no significant change occurred.(4)With the increase of dry density,the effective internal friction angle and cohesion of tailing materials increase;with the increase of moisture content,the effective cohesion decreases gradually,but the effective internal friction angle has no obvious change;with the increase of drying-wetting cycles,the effective cohesion decreases gradually,and the internal friction angle tends to be stable after a small fluctuation.(5)Combined with the mechanical properties of tailings,according to the theory of soil damage mechanics,a statistical damage constitutive model suitable for tailings is proposed,This model can reflect the volume deformation of the tailings sample after the shear test and the strength characteristics after the sample is destroyed.