A model of seepage field in the tailings dam considering the chemical clogging process

摘要

The radial collector well, an important water drainage construction, has been widely applied to the tailings dam. Chemical clogging frequently occurs around the vertical shaft in radial collector well due to enough dissolved oxygen and some heavy metals in groundwater flow of tailings dam. Considering the contribution of water discharge from both vertical shaft and horizontal screen laterals and chemical clogging occurring around vertical shaft well, a new model was developed on the basis of Multi-Node Well (MNW2) package of MODFLOW. Moreover, two cases were calculated by the newly developed model. The results indicate that the model considering chemical clogging occurring around the vertical shaft well is reasonable. Owing to the decrease in hydraulic conductivity caused by chemical clogging, the ground-water level in dam body increases constantly and water discharge of radial collector well declines by 10-15%. For ordinary vertical well, it decreases by 30%. Therefore, chemical clogging occurring around radial collector well can arouse increases of groundwater level, and influence dambody safety.