Geosynthetics reinforcement application for tsunami reconstruction: Evaluation of interface parameters with silty sand and weathered clay

Great attention is directed to rebuild livelihoods and rehabilitate coastal communities affected by the Tsunami in the Indian Ocean in South Asia. It takes years of effort of different engineering disciplines to recover from recent devastations caused by the Tsunami. Geosynthetics can play important and vital roles in the protection, mitigation and rehabilitation efforts in affected coastal areas. Geosynthetics can be applied for reinforcement, filtration, drainage, protection, lining, and containment. Particularly, geotextiles can be used effectively for erosion protection and for reinforcement of earth embankments to resist failure during the occurrence of earthquakes associated with tsunami. Presented in this paper is the interaction behavior at pullout interfaces of high strength geotextile confined in weathered clay and silty sand. The interface parameters which are needed for both finite element and conventional analyses of geotextile-reinforced earth structures such as the local shear stress/shear displacement, the interface interaction coefficient and the in-soil stress/strain of the reinforcement have been successfully interpreted by the newly proposed method considering the softening behavior and non-uniform distribution of shear stress along the extensible reinforcement. Results from this study indicate that the interpretation of pullout tests using conventional methods underestimated both the shear stiffness and the peak shear strength at the pullout interface of extensible reinforcement.