预制桩为标准化长度,合理可靠的拼桩接头可促进预制围护桩的推广应用。采用翼缘 L 型钢板-钢连接板-高强螺栓的接头形式连接预应力混凝土预制工字型桩端,通过剪切试验研究了该接头的剪切破坏模式及抗剪承载能力,并建立有限元模型对接头的剪切破坏过程进行了数值模拟,在试验验证的基础上,采用有限元分析方法研究了混凝土强度、连接钢板强度、预应力混凝土(prestressed concrete, PC)钢棒数量对桩接头抗剪承载力的影响。研究结果表明：考虑塑性损伤的三维精细化数值模拟结果与试验结果吻合较好;随着剪切荷载的增加,接头处顶、底部的连接钢板及顶部 PC 钢棒先于其他部位屈服;改变混凝土强度和顶部的纵向 PC 钢棒数量,可显著改变接头的抗剪承载力; 而改变连接钢板屈服强度,对承载力影响并不明显。

The lengths of precast piles are normalised, and a reliable pile joint can facilitate the application of prefabricated retaining piles. In this study, the joint used for connecting the ends of prestressed concrete I-piles was composed of an L-shaped flange steel plate, a steel connection plate, and high-strength bolts. The shear failure mode and capacity of the joint were evaluated through shear tests, and a finite element model was established to simulate the shear failure process of the joint. Based on the experimental verification, the effects of the strength of concrete, the strength of the connecting steel plate, and the number of PC steel bars on the shear bearing capacity of pile joints were analysed through finite element simulation. The results showed that the three-dimensional fine numerical simulation considering plastic damage could predict the joint response. With the increase in the shear load, the connecting steel plate and top PC steel bars near the joint yielded before other parts. The variations in concrete strength and the number of top longitudinal PC bars significantly influenced the shear capacity of the joint. However, the increase in the yield strength of the connecting steel plate had no significant effect on the bearing capacity.