In order to improve the bearing characteristics of prestressed high-strength concrete (PHC) piles, this paper proposes the use of steel strands and steel bars instead of steel reinforcement for PHC piles or PHC piles wrapped in BFRP. Eight PHC piles were tested under low-cycle loading to study their seismic performance. Through the analysis of the test phenomena, hysteresis curve, skeleton curve, strength and stiffness degradation, ductility and energy dissipation, it is found that the bearing capacity of the PHC pile coated with BFRP is much higher than that of the other types of piles. The PHC piles with steel bars and steel strands as the main reinforcement have the best seismic performance. ABAQUS was used to establish nonlinear finite element models. The results show that the experimental results are in good agreement with the finite element results. In addition, it is found that increasing the reinforcement ratio has no effect on improving the bending capacity of the PHC pile, while increasing the reinforcement ratio of the main reinforcement can improve the ultimate bending moment of the PHC pile.

中文翻译：

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新型PHC桩抗震性能的试验研究。

为了改善预应力高强混凝土桩的承载特性，本文提出用钢绞线和钢筋代替钢筋加固的PHC桩或BFRP包裹的PHC桩。在低循环荷载下测试了八根PHC桩，以研究其抗震性能。通过对试验现象，滞回曲线，骨架曲线，强度和刚度退化，延性和能量耗散的分析，发现采用BFRP涂层的PHC桩的承载力要远远高于其他类型的桩。以钢筋和钢绞线为主要钢筋的PHC桩具有最佳的抗震性能。ABAQUS用于建立非线性有限元模型。结果表明，实验结果与有限元结果吻合良好。另外，发现增加配筋率对提高PHC桩的抗弯能力没有影响，而增加主筋的配筋率可以改善PHC桩的极限弯矩。