EXPERIMENTAL INVESTIGATION OF INTERFACIAL FRICTION BETWEEN FRPs-WRAPPED STEEL SURFACE AND COHENSIONLESS SOIL

Steel piles are nowadays commonly used as a foundation component. The soil and steel surface interaction plays a major role in transferring the load to the soil. This study was carried out to examine the interfacial frictional behaviour of cohesionless soil and a steel surface wrapped with different types of fibre-reinforced polymers (FRPs). Conventional direct-shear tests were conducted on steel plates wrapped with FRP sheets. Fibre-reinforced polymers like unidirectional carbon, basalt, aramid and glass were wrapped on steel plates and tested at different orientations with respect to the applied shear. Two different soil samples were taken for the study, viz., well-graded and poorly graded sand. The experimental results showed that the interface friction increased with the surface roughness and also with the orientation of the fibres to the loading direction. The study also showed that the gradation of sand plays a vital role in the interfacial shear strength of the sand and steel surface wrapped with different types of fibre-reinforced polymers.