（1浙江大学建筑设计研究院有限公司，杭州 310028；2 浙江大学平衡建筑研究中心， 杭州 310028；3 宁波一中管桩有限公司， 宁波 315450； 4 浙江大学结构工程研究所， 杭州 310058）

［摘要］结合先张法预应力离心混凝土钢绞线桩端板的特点，提出了一种抱箍式U形连接卡箍的机械连接方法。通过对8根先张法预应力离心混凝土钢绞线桩试件进行足尺度抗拉性能试验，研究先张法预应力离心混凝土钢绞线桩及其机械连接接头的抗拉承载力、变形延性及破坏特征等。试验结果表明：桩身混凝土裂缝分布均匀且密集；试件的开裂抗拉承载力、极限抗拉承载力试验值均大于相应的理论计算值；破坏形式为桩身混凝土受拉后裂缝宽度超过限值或非预应力钢筋与端板拉脱；抱箍式U形连接卡箍安全可靠。

［关键词］抗拉性能；先张法预应力；钢绞线桩；离心混凝土；抱箍式U形连接卡箍

中图分类号：TU473文献标识码：A文章编号：1002-848X(2021)03-0115-06

Experimental study on tensile performance of pretensioned prestressed centrifugal concrete steel stranded pile and its mechanical connection joints

GAN Gang1,2, ZENG Kai1, YU Xiaodong3, GONG Shunfeng4, CHEN Gang1, XU Quanbiao1

(1 The Architectural Design & Research Institute of Zhejiang University Co., Ltd., Hangzhou 310028， China;2 Center for Balance Architecture, Zhejiang University, Hangzhou 310028, China;3 Ningbo Yizhong Pipe Pile Co., Ltd., Ningbo 315450, China； 4 Institute of Structural Engineering,Zhejiang University, Hangzhou 310058, China）

Abstract:Combined with the characteristics of the end plates of the pretensioned prestressed centrifugal concrete steel strand piles, a mechanical connection method of the U-shaped connecting clamp with a hoop was proposed. The tensile bearing capacity, deformation ductility and failure characteristics of pretensioned prestressed centrifugal concrete steel strand piles and their mechanical connection joints were studied through the full-scale tensile performance test of eight specimens of pretensioned prestressed centrifugal concrete steel strand piles. The test results show that the crack distribution of pile concrete is uniform and dense. The test values of the cracking tensile bearing capacity, ultimate tensile bearing capacity of the specimens are both larger than the corresponding theoretical calculation values. The failure mode is that the crack width of pile concrete after being pulled exceeds the standard or the non-prestressed steel  and end plate are pulled out. The  U-shaped connecting clamp with a hoop is safe and reliable.

Keywords:tensile performance;pretensioned prestress;steel stranded pile;centrifugal concrete;U-shaped connecting clamp with a hoop

作者简介：干钢，博士，研究员，博士生导师，Email: gang@zuadr.com。