<p>Static liquefaction has become a major cause of recent catastrophic tailings impoundments failures. To enhance the structural integrity of impoundments, a new co-disposal strategy has been proposed, incorporating waste rock inclusions (WRIs) within the impoundment. While previous studies have primarily focused on the seismic performance of WRIs-enhanced tailings impoundments, their impact on the static liquefaction potential of tailings and performance of tailings impoundment remains underexplored and not well understood. In this paper, the influence of WRIs on the performance of tailings impoundments under static loading conditions were investigated by modelling the staged construction of an upstream tailings impoundment both with and without WRIs. The results indicate that WRIs can significantly enhance the static performance of tailings impoundments by accelerating drainage and minimizing the static liquefaction potential of mine tailings. This leads to lower pore water pressures, horizontal displacements, state parameter, and an almost drained condition for tailings near WRIs than the case without WRIs. Consequently, the maximum PWP and horizontal displacement for the reinforced impoundment can be up to 41% and 28% lower, respectively, than in the unreinforced impoundment. Furthermore, stability analyses throughout the staged construction demonstrate that the factor of safety (FoS) for reinforced impoundments are 72% and 85% higher than the unreinforced case under peak and post-peak strength conditions, satisfying the minimum requirement. WRI offers an effective method for minimizing the static liquefaction potential of mine tailings, thereby enhancing the overall stability of impoundments.</p>