Numerical Modeling of the Lateral Behavior of Concrete-Filled FRP Tube Piles in Sand

Abstract

In this study, a numerical model is developed to study concrete-filled FRP tube (CFFT) pile behavior and interactions with foundation soil under lateral loading. The model, based on nonlinear finite element analysis (NFEA) and the disturbed state concept (DSC), considers material and geometrical nonlinearity as well as the interface of soil with fiber-reinforced polymer (FRP). Furthermore, the structural and geotechnical performance of the interface of soil and CFFT pile is studied by utilizing 3D finite element models (FEMs) of full-scale field tests conducted during the construction of a highway bridge on Route 40 in Virginia. 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. The FRP thickness had the least impact on the results.