The application of pretensioned spun high-strength concrete (PHC) piles in high-intensity seismic areas has been limited by insufficient horizontal load resistance and poor deformation capacity. A new type of pretensioned spun concrete pile with high-strength and high-elongation steel strands instead of steel bars has been developed. This paper presents a flexural performance evaluation of the new centrifugal spun concrete pile with steel strands (hereafter referred to as a PSC pile). An experimental study is presented first, including bending tests on six full-scale pile test specimens with three different pile diameters. The flexural performances of PHC and PSC piles are comparatively assessed. The results show that the new PSC piles have similar crack resistance, but higher ultimate bearing capacity and better deformation capacity under a flexural condition. Compared with PHC piles, which exhibit a brittle bending failure, PSC piles demonstrate a ductile bending failure. Following the experimental study, a theoretical model is developed to evaluate the flexural strength of the piles, and a simplified calculation equation for ultimate bending moment is proposed. Finally, a finite-element model is established to simulate the flexural performance of the piles; the modelling results are found to be in good agreement with the experimental results.

中文翻译：

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钢绞线加固预张拉混凝土桩的抗弯性能

预张法高强混凝土（PHC）桩在高烈度地震区的应用一直受到抗水平承载能力不足和变形能力差的限制。研制了一种采用高强度高伸长钢绞线代替钢筋的新型预张法旋压混凝土桩。本文介绍了一种新型钢绞线离心旋压混凝土桩（以下简称 PSC 桩）的抗弯性能评估。首先介绍了一项实验研究，包括对具有三种不同桩径的六个全尺寸桩试样进行弯曲试验。对PHC和PSC桩的抗弯性能进行了比较评估。结果表明，新型 PSC 桩具有相似的抗裂性，但在弯曲条件下具有更高的极限承载能力和更好的变形能力。与表现出脆性弯曲破坏的 PHC 桩相比，PSC 桩表现出延性弯曲破坏。在试验研究的基础上，建立了评价桩体抗弯强度的理论模型，并提出了极限弯矩的简化计算方程。最后，建立有限元模型来模拟桩的抗弯性能；建模结果与实验结果吻合较好。并提出了极限弯矩的简化计算方程。最后，建立有限元模型来模拟桩的抗弯性能；建模结果与实验结果吻合较好。并提出了极限弯矩的简化计算方程。最后，建立有限元模型来模拟桩的抗弯性能；建模结果与实验结果吻合较好。