GEOSYNTHETIC LOADS IN LANDFILL SLOPES - DISPLACEMENT COMPATIBILITY

Soil and geosynthetic components are used together in lining and cover systems for waste-containment facilities to protect the environment by acting as a hydraulic barrier. Since the performance of the barrier depends on the components remaining intact, accurate predictions of tensile loads in the components are important. Lining and cover-system components must be designed to resist tensile loads anticipated. Four methods for determining tensile loads are examined in this paper. Two common design methods, called the limit equilibrium method (LEM) and the limit method (LM), that consider only force equilibrium to predict tensile loads are compared with two proposed methods that consider both force equilibrium and displacement compatibility. An example multiple-layered cover system is used to compare predictions from the four methods. The comparison indicates that displacement compatibility is an important consideration and can influence predictions significantly for tensile load. Estimates of tensile load in the geosynthetics using the state of practice may be too great (as for the LM) or too small (as for the LEM), compared with more rigorous displacement compatibility methods.