In South Africa and indeed globally, there is, and will be for the foreseeable future, a need for landfills for the final disposal of waste.

Suitable sites for these landfills have become scarce, and as a result, even though they are more costly to engineer, sites with slopes greater than 1 in 4 are becoming more commercially viable. The design of lining systems for steep slopes however, poses significant technical challenges.

This paper discusses and presents the results of an investigation to determine the performance and stability of a Class B landfill lining system on various slope angles.

The Class B landfill lining system was assessed in terms of the prescribed mineral layers, geosynthetic materials and alternatives of equivalent performance.

The factors of safety for stability on slopes of 1:4, 1:3, 1:2 and 1:1 using 2-D limit equilibrium analyses were calculated.
The results of the various factors of safety are presented, showing a distinct exponential relationship.

Download technical paper here.