Reliability-based critical rainfall pattern curve for slope stability of tailing dams

To address the effects of rainfall and variability in soil parameters on the slope stability of tailing dams, the existing Factor of Safety (FoS)-based critical rainfall pattern curve (CRPC) is extended to a reliability-based CRPC. The proposed reliability-based CRPC is illustrated through a simplified tailing dam. The results have shown that there exists a specific rainfall intensity (named safe rainfall intensity), below which the slope of tailing dams will be in a safe state no matter how long the rainfall duration is. The larger the safe rainfall intensity, the higher the safety margin for the slope stability of tailing dams. A greater saturated permeability coefficient leads to a larger safe rainfall intensity. A longer length of dry beach results in a higher safety margin for the slope stability of tailing dams. The presence of a drainage pipe contributes most to the increase in the stability of tailing dams under rainfall infiltration. The FoS-based CRPC tends to overestimate the safety margin of the slope stability of tailing dams, owing to the omission of variability in soil parameters as compared with the reliability-based CRPC. An earlier warning plan will be made based on reliability-based CRPC than based on FoS-based CRPC.