Numerical Simulation of Dynamic Response of GFRP Tubular Concrete-Filled Active Pile Groups Under Seismic Loads

Background

Pile foundations, whether precast or cast-in-situ, are widely used in essential structures such as bridges and jetties. The common materials for pile fabrication include concrete, steel, and wood. However, these materials can deteriorate in harsh environments such as seawater and salty soil, affecting the integrity and service life of the pile-foundation systems.

Problem

Traditional solutions, like using concrete piles confined with steel jackets, increase service life but are costly. The engineering community is exploring fiber reinforced polymer (FRP) as an alternative due to its noncorrosive nature and resistance to harsh environments. However, the relatively short track record of FRP raises concerns about its behavior under non-normal conditions, such as seismic events.

Objective

To present a numerical assessment of the seismic behavior of an offshore bridge supported by a GFRP-filled tube pile group, considering the soil-structure interaction (SSI) and dynamic behavior of the composite system.

Methods

The study involves a detailed proposed methodology for assessing the structure under earthquakes with different soil profiles. A numerical model is developed to evaluate the dynamic response and interaction between soil and the GFRP-filled tube pile group.

Results

The results verify the expected benefits of using GFRP in pile foundations, focusing on the effects on the lateral capacity of structures under seismic conditions.

Conclusion

The study contributes to understanding the feasibility and performance of GFRP-filled tube piles in offshore bridge foundations under seismic loads, providing insights into their potential advantages and limitations.