Analysis of Geosynthetic-Reinforced Tailings Dam Slopes Subjected to Surface Loads

Abstract

This study presents an extensive numerical investigation of the stability of a geosynthetic-reinforced tailings dam embankment slope subjected to surface loads from retained pyrite tailings slurry upstream of the dam. The analysis was performed on an embankment with an inclination of 1V:2.5H on the upstream slope and 1V:2H on the downstream slope. The dam embankment rests directly on previously deposited pyrite tailings that have dried over time and are sufficiently consolidated to support the embankment. The variable parameters considered in this study include the geosynthetic reinforcement length across the failure zone, effective cohesion ( c′ ), effective angle of internal friction ( ϕ′ ), total unit weight of the embankment clay ( γ ), and the number of reinforcement layers ( N ). The results revealed that the safety factor of the embankment slope increased with the increasing length of the geosynthetic reinforcement across the failure zone, shear strength parameters c’ and φ ʹ , and unit weight, $$\gamma $$ . Increasing the total unit weight of embankment clay from 13 kN/m 3 to 21 kN/m 3 resulted in a 61%, 47%, and 30% increase in the factor of safety for N  = 13, 7, and 4, respectively. Additionally, for every 1 kPa increase in c’, which is a very low value, the safety factor increased on average by 2.5%, 2.2%, and 1.9% for N  = 13, 7, and 4, respectively. The findings of this study contribute to the advancement of safer and more reliable tailings dam designs by offering innovative and cost-effective solutions to engineering challenges.