Numerical Modeling of Concrete-Filled Fiber-Reinforced Polymer Piles

Abstract

Although many studies have been conducted on the structural behavior of concrete-filled fiber-reinforced polymer (FRP) tube (CFFT), the soil-structure interaction of CFFT piles was not previously considered. In this study, a numerical model is developed to study CFFT pile behavior and interactions with soil foundation under lateral loading. The model, based on nonlinear finite element analysis (NFEA) and the disturbed state concept (DSC), considers material and geometrical nonlinearities as well as the interface of soil with the CFFT pile. The finite element model was verified against a full-scale field test from the literature conducted during the construction of a highway bridge. Based on deflection along the length of the pile, the model results are in good agreement with the experimental data. To investigate the effects of various parameters on the behavior of CFFT piles and local buckling, a parametric study was also performed on different geometrical and material properties, including the pile diameter to length ratio, FRP tube thickness, concrete strength, and soil properties. It was found that the surrounding soil and length to diameter ratio exerted the most noticeable influence, followed by concrete strength while the FRP thickness had the least impact on the results.