Abstract:
Geosynthetics are widely used as a main part of the landfill barrier system to prevent contamination
leaking into surrounding environment. To design the landfill liners system, stability of landfills must be considered
dependening on the interaction mechanism between geosynthetics liner system which mainly influence to tensile
forces within geosynthetics. The purpose of this thesis is to investigate the interaction mechanism for 8 interfaces
types between geosynthetics and clay liners. A series of laboratory tests were conducted using a direct shear test
having dimensions of 100 x 100 mm. From testing results, the interaction mechanism was affected by interface
types and testing conditions (wet and dry conditions). The interface shear strength increased with increasing
normal stress. The proposed hyperbolic model can be employed to simulate the stress-strain relationships of
the interface between geosynthetics and clay liner. The proposed model was successfully implemented into
the numerical program (ABAQUS) for simulation of landfill liners system behaviors. From the parametric
studies by numerical analysis, the geosynythetics tensile forces increased with increasing slope angle, protection
layer thickness and geosynthetics stiffness. Geosynythetics tensile forces increased with decreasing strength
of protection layer and strength of interface. The tensile forces were increased when the slope angles of liners
system were greater than 20 degrees and without buttress resistance at toe slope. From the parametric studies,
the preliminary design guideline for the geosynthetics tensile force in landfill liner system was proposed.