Abstract
We have proposed a new reinforcement technique called Hybrid Sandwiched Reinforcement (HBS) where the thin sand layers are placed above and beneath the geosynthetics to increase the mechanical potentials of cohesive soil embankment and foundations. This reinforcement method has the advantages that reinforcement improvement as well as maintenance of hydraulic conductivity which is more marked than the cases without the sand layer. Successive to the previous works by the authors, in the present study, we performed small scaled-model tests on embankment with and without reinforcement with and without sand layer placed. The results from model tests are interpreted with a special emphasis on the improvement of toughness of embankment reinforced with HBS. It is made clear that HBS plays a role to improve the toughness more markedly than the case with conventionally-adopted placement geosyntheitcs in clay embankment. It is inferred from the results from direct-shear tests on investigation of the interaction between geosynthetics and sand that this improvement of toughness of embankments is caused by the increased frictional force exhibited between geosynthetics and sand.
