The Use of Accurate Pore Pressure Monitoring for Risk Reduction in Tailings Dams

Simply monitoring movement of the tailings dam wall does not address the cause of tailings dam failures and will therefore never be an effective method to reduce or prevent failures. Monitoring the causes of failures is more effective. The main cause of tailings dam failure is slope instability, which is caused by too much water in the wrong place. Accurate pore pressure monitoring of the pressure (weight) of water in the tailings storage facility (TSF) slopes and plotting of flow lines beneath and upstream of the TSF can guide and enable early intervention to prevent or delay failure. Remote monitoring linked to artificial intelligence and robotics to turn on pumps and open drains to address and remove the cause of failure can help reduce risk. Installation of multiple point piezometers in an accurate pattern allows the plotting of equipotentials and flow lines in three dimensions. Each TSF is unique and requires its own monitoring design, which should be tailored to match the age, structure, and specific causes of risk. Once understood, the monitoring system can be coupled to a reporting system to significantly reduce the risk of failure at both legacy and active sites.