Stability analysis on veneer cover system for landfill considering the effect of internal seeper

Abstract

Abstract A drainage layer can easily cause clogging during rainfall, and a retained seeper may cause a strong uplifted-floating effect on the overlying soil layer, thereby inducing serious disasters. This paper proposes two failure modes (i.e., direct-slip failure and uplifted-floating failure) that may be encountered simultaneously by the cover soil layer of landfills. Corresponding analytical models and computing methods are established. Results demonstrate that both failure modes can potentially occur on the cover system but exhibit different performance levels. The immersion ratio (λ) of the drainage layer is an important factor influencing the safety factor (FS) of both failure modes. By increasing the λ-value, the Fs-values of both failure modes decrease evidently, but the decrease rates are vastly different. Moreover, the effects of other parameters such as slope length and slope angle on the FS of the two failure modes are also discussed in this study. Results indicate that these parameters exhibit different effect degrees on the occurrence of the two failure modes. Finally, the Fs-values of the direct-slip failure calculated in this study are compared with the results of others , and indicated that the reliability of this study is high. The results of this study can optimize the design parameters of the landfill final cover system and render its stability evaluation more accurate.