Determination of bearing capacity of fiber-reinforced polymer screw piles via field loading tests

This study investigated the pull-out performance of fiber-reinforced polymer (FRP) screw piles using full-scale field loading tests. FRP screw piles are lightweight, corrosion-resistant alternatives to traditional piles, particularly suited for soft ground (i.e., saline reclamation sites) applications such as solar power structures. The results demonstrates that the screw blade geometry, especially the tip area, affects the pile’s load-bearing capacity, with a minimum effective tip resistance area of 785.4 cm² required for optimal performance. The field tests results reveal that increasing the number of screws has no impact on the bearing capacity when the blade is sufficiently wide. Additionally, conventional methods for estimating bearing capacity are inadequate for FRP screw piles, necessitating a revised design approaches. Based on the test results, optimized specifications for FRP screw piles are proposed to improve their performance for weak ground conditions. This study provides practical insights for the adoption of FRP screw piles in challenging environments where they offer a durable, efficient, and sustainable solution for foundations. • Trial Construction of FRP Screw Pile in saline reclamation site. • Proposing optimized specifications for FRP screw piles. • Measured a minimum effective tip resistance area. • Suggestion of screw dimensions considering load resistance performance.