Abstract
A series laboratory large scale direct shear tests were conducted to investigate interface shear strength between geomembrane (GM) and clayey soils. Two types GMs tested were made of polyvinyl chloride (PVC) (GM-1) and polyethylene (PE) (GM-2) respectively with a thickness of 1.0 mm. Two types soil used were mixture of Ariake clay and passing 425 μm sieve decomposed granite (mixed soil), and Na-type bentonite. For all cases investigated, the interface shear strength (τf) was lower than the shear strength of the soil (τfs) and the lowest τf /τfs ratio was about 0.55. GM-1 is softer and resulted in higher apparent interface adhesion. The test results also show that the higher the water contents of the soil, the lower the τf value. GM-2/bentonite interface only had a friction angle of 3° ~ 4°. The results from this study can be applied for design liner system of landfill.
