<p>Pile foundations are widely used for tall and multistoried constructions. The performance of pile foundations under vertical and lateral loads is significant in the design. Strengthening of these foundations is required to resist the increase in loads arising from change in use of the structure or due to design or construction errors. Now a days Fibre reinforced polymer (FRP) has been widely used as a strengthening material. High tensile strength, lightweight and anti-corrosion properties of FRPs have made them suitable for addressing the above problems. Many studies have been done with concrete piles and less on FRP strengthened steel piles. Hence in this study, model steel hollow piles fitted with pile cap and wrapped with FRP were chosen and tested under axial compressive load in cohesion less poorly graded soil. The orientation of fibres have significant impact on the interface friction and strength of the piles. Hence all fibres were chosen as unidirectional fibres. They were wrapped as fibre orientation parallel to shear, namely, along the length, and fibre orientation perpendicular to shear, namely, along the circumference. Also to find the effect of surface roughness on the performance of the steel piles, different rough surfaces developed using abrasive sheets wrapped on the steel piles were also studied. To study the effect of length to diameter (l/d) ratio, two different diameters of steel pile of the same length were chosen. To have a better understanding on the FRP-soil interface behavior, experimental studies were performed. The behavior of steel-soil interface was compared with FRP-soil interfaces and also with abrasive-soil interfaces. Experimental results showed significant changes in the interface friction angle with variation in soil gradation, orientation of fibres and surface roughness. Pile Load tests are done to investigate the influence of interface friction on the load carrying capacity of the piles. To predict the ultimate driving resistance of piles in soils, pile driving was done by using hammers. The static load test was done as maintained load test and the ultimate load was calculated from load-settlement curves as per IS code 2911-Part4 (2010) provisions. The ultimate load of FRP wrapped piles were increased compared to the unwrapped steel pile in the load tests. The Glass fibre reinforced polymer (GFRP) wrapped steel pile had higher ultimate load carrying capacity and Carbon fibre reinforced polymer (CFRP) had the least load carrying capacity than the other FRPs. The fibre orientation along the circumference had a higher load carrying capacity than the fibre orientation along the length. The results showed that interface friction plays a vital role in deciding the pile capacity, which is influenced by the diameter of the pile, surface roughness, and fibre orientation. The numerical validation of the experimental results were done by finite element method using the software ANSYS Workbench.</p>