Stability Analysis of Cemented Tailings Backfill in Stope Considering Layered Structural Characteristics

Abstract

In this study, the stage subsequent to filling mining is selected as the background, and the cemented tailings backfill serves as the research object. Given the effects of the layer effect, top load, lateral pressure coefficient, and so forth, a safety factor calculation model of cemented tailings backfill in large depth–width ratio stopes is developed in accordance with the Mohr–Coulomb failure criterion, which is compared with the models proposed by other scholars. Lastly, the characteristics of the effect exerted by a wide variety of factors are discussed. As indicated by the results, (1) there are three scenarios in the position of the sliding surface, located in the first layer, passing through two layers and passing through three layers, and mainly the first two. Compared with other models, the rationality and reliability of the model in this study are verified. Different models have different research backgrounds and different focuses, and certain differences exist in results. (2) The safety factor of cemented tailings backfills is reduced with the increase of the top load, the lateral pressure coefficient, and the bulk density, while it is increased with the increase of cohesion, internal friction angle, and bonding force ratio. Furthermore, a linear functional relationship exists between them. The safety factor has the maximum sensitivity to cohesion and the minimum sensitivity to top load. (3) Using Statistical Package for the Social Sciences (SPSS) software for regression analysis, a simplified multiple linear regression equation between the safety factor and the respective factor is built. The regression results achieve an error of 10%. As revealed by the result of this study, the simplified regression equation can be applied to the stability evaluation of the on-site cemented tailings backfill.