Geosynthetic liner integrity and stability analysis for a waste containment facility with a preferential slip plane within the liner system

Abstract

The paper examines the effects of settlement-induced downdrag on geosynthetic liner systems for a waste containment facility with steep side slopes for different design scenarios, and conducts the stability analysis of the waste mass during waste filling operations. Without the presence of a reinforcing layer above a geomembrane (GMB) liner, the liner experiences unacceptable tensile strains under both short- and long-term downdrag waste settlements. It is shown that an anchored high strength/stiffness geotextile (HS-GTX) reinforcement over the GMB can reduce the GMB tensile strains to less than 3%, but the HS-GTX itself may be overloaded. A geosynthetic slip layer over the full or partial HS-GTX reinforcement overlying the GMB can reduce the tensile strains of the GMB to less than 3% and of the HS-GTX to less than 5% by providing a preferential slip plane between the geosynthetic slip layer and the HS-GTX. A rupture of the geosynthetic slip layer is likely to occur resulting in the exposure of the HS-GTX to the waste, but the protection of the GMB by the HS-GTX is still expected. The results from the stability analysis show that, during waste filling operations under a given factor of safety, there is a critical relationship between the width of the top of the waste pile and the total waste thickness.