Behavior of Confined Concrete Filled FRP Tube Under Lateral Loads

Hamed, Mohamed; Alaraby, Ibrahim; Elbarbary, Ahmed Hesham; El-Gendy, Mahmoud

doi:10.21608/pserj.2025.373479.1403

Behavior of Confined Concrete Filled FRP Tube Under Lateral Loads

Document Type : Original Article

Authors

¹ civil engineering department, faculty of engineering, portsaid university

² Department of Civil Engineering, Faculty of Engineering, Delta University for Science and Technology, Egypt

³ Civil Engineering Department , Faculty of Engineering, PortSaid University, Portsaid, Egypt.

⁴ Civil Engineering Department, Faculty of Engineering, Port Said University

10.21608/pserj.2025.373479.1403

Abstract

This paper presents the application of advanced numerical modeling in geotechnical engineering for analyzing the lateral load response of confined concrete-filled fiber-reinforced polymer (FRP) tube piles, addressing the growing need for innovative foundation solutions in challenging soil conditions. Extending the authors' previous investigations into laterally loaded piles and confined concrete-filled FRP tubes, the developed numerical approach, a hybrid technique implemented in GEOTools software, utilizes the P-y curve method to model nonlinear soil behavior and incorporates nonlinear material properties derived from the stress-strain characteristics of the FRP tube and confined concrete. The technique was used to investigate the influence of key material and geometric parameters, including concrete compressive strength and diameter-to-thickness ratios, on the pile's load capacity, deformation, and stability. The numerical framework's accuracy is validated against interaction diagrams from international design codes, experimental data, and analytical results from the literature. Furthermore, a practical application is demonstrated by modeling FRP piles in a realistic East Port Said subsoil profile. Results show a strong correlation between pile geometric ratios and lateral performance. Maximum bending moment and shear force were found to be influenced by the length-to-diameter ratio up to 15, beyond which further increases had no impact as the pile reached its effective length. Additionally, increasing the diameter-to-FRP thickness ratio enhanced moment and shear resistance.

Keywords