中文摘要：

为了提高混凝土预制方桩的连接性能,重新设计了桩身的连接接头.通过对3种常用桩型共9根复合配筋混凝土预制方桩接头试件进行足尺度抗弯性能试验,研究方桩连接接头的抗弯承载力、变形延性及破坏特征等.结果表明：方桩接头试件破坏时,桩身混凝土裂缝分布紧密,裂缝竖向发展分叉较多,部分裂缝相互交错;复合配筋混凝土预制方桩接头试件的极限抗弯承载力试验值远大于桩身极限抗弯承载力规范公式的计算值,且都大于50%以上;方桩接头试件破坏形式主要有两种：桩身正截面抗弯破坏和端板与桩身连接破坏,发生桩身正截面抗弯破坏的接头试件具有更好的承载能力和变形性能.

英文摘要：

The connection joint of the pile was redesigned to improve the connection performance of concrete prefabricated square piles.The full-scale flexural performance experiments of nine connection joint specimens of composite reinforcement concrete prefabricated square pile for three kinds of commonlyused pile types were conducted to analyze the flexural capacity,deformation ductility and failure characteristics of the connection joint.The test results show that the concrete cracks in the pile are closely distributed and have more bifurcations at the connection joint specimen failure of square piles,and some of them are staggered with each other.The experimental result of the ultimate flexural capacity of the connection joint specimen for composite reinforcement concrete prefabricated square pile is all over 50%greater than the calculated value of the ultimate flexural capacity of the pile body from the specification formula.The connection joint specimens of the square pile have two kinds of failure modes,i.e.the flexural failure of pile body and the connection failure between the end-plate and the pile body.For the flexural failure of the pile body,the connection joint specimen has better flexural capacity and deformation performance.