基于改良渗透系数的尾矿库污染物运移模拟

 采用Fredlund解析关系式描述渗透系数与基质吸力之间的关系,对渗透系数取值进行函数方式改进,探讨了渗流条件下重金属运移过程。基于渗流理论建立起尾矿库污染物迁移的二维数值渗流场模型,应用有限元方法进行运算求解,将计算得到的渗流场结果作为母模型,引入溶质迁移子模型进行耦合运算。计算结果表明,尾矿库服役期间周围土壤中重金属离子污染物的迁移范围不断扩大,污染物浓度随着迁移距离的增大而逐渐变小。计算显示,从第2750天开始重金属污染物在渗流的作用下开始在土壤边坡中显露,并对周围环境产生影响,并得出污染源在渗流条件下的迁移路径。渗透系数经改良之后的计算结果与该尾矿库重金属污染监测情况相符,在模型误差允许的情况下其计算结果可靠。

Research on Transport of Tailings Contaminant Based on Improved Permeability Coefficient

Fredlund analytic relations function was used to describe the relationship between the coefficient permeability and the matric suction, through which the permeability coefficient was improved to be a function, and heavy metal migration process under the seepage conditions was explored. A two-dimensional numerical migration model of tailings contaminants was established based on the percolation theory, and the finite element method was used to solve the model. Coupled with the solute transport sub-model, the seepage results were used for calculation as the parent model. The results show that, during the service of the tailings, the migration of heavy metal ion contaminants expands their scope and size in the surrounding soil, the concentration of the contaminants becomes smaller and smaller with the distance of migration increases. The contaminants exposed beyond the slope begins to impact on the surrounding environment when the migration of heavy metal contaminant model is calculated under seepage by 2750 days, and the migration paths of the contaminant are concluded under the seepage conditions. The results calculated by the improved permeability coefficient conform to the environmental monitoring data of the tailings. Under the condition of the allowed model error, the computation results are reliable, which can provide a theoretical basis for the safety management and environmental monitoring of tailings.