Study the Effect of Interface Friction on the Behaviour of Fiber-Reinforced Polymer Piles under Axial Loads

Abstract

Fiber-reinforced polymer (FRP) composites provide potential alternatives for overcoming interface problems between conventional piling materials (wood, concrete, and steel) and soil. FRP composites are corrosion resistant, and more durable than conventional materials. More research is required to adapt these new materials to geotechnical practises. This study examines the enhancement of interface friction between glass FRP (GFRP) piles and sandy soils. The research comprises two phases. Phase I is an experimental study using direct shear test on the interface between sandy soils and sand coated GFRP composites. Phase II presents testing 5 small scale sand coated GFRP piles under axial loading in a soil tank. Phase I results indicate that GFRP surface roughness has a significant effect on GFRP-sand interface friction. Phase II results show that coating GFRP piles with silica sand significantly increases pile friction resistance in sand under axial loads with optimum sand coating ratio 1500 g/m2