Axial Behavior of Innovative Sand-Coated GFRP Piles in Cohesionless Soil

Abstract

In pile construction, conventional pile materials such as concrete, steel, and wood are frequently subject to soil–substructure interaction durability problems due to corrosion and deterioration. Fiber-reinforced polymers (FRPs) provide a potential alternative to eliminate the durability problems of conventional materials. This paper describes the results of an experimental study on the effect of the interface on the behavior of glass FRP (GFRP) piles jacked into dense sand under axial loads. The aim of this study is to introduce an innovative GFRP piles in cohesionless soil through coating its surface with silica sand to enhance the pile interface behavior. The experimental program investigates seven small-scale GFRP piles with different surface roughness and a reference steel pile used as a control. The surface of five of the seven GFRP piles was coated with silica sand, and the performance of the GFRP piles was compared with that of the control steel pile. The results of the pile load tests were analyzed by using three different commonly used methods to determine the ultimate pile load capacities. The results showed that the innovative mechanism of coating GFRP piles with silica sand enhanced the interface friction of the GFRP piles in sand under axial loads and increased the ultimate pile load capacity in comparison with that of the control piles.