摘要
为了提高混凝土预制桩与承台连接的施工质量和效率,研发了一种用于预应力混凝土管桩与承台连接的机械连接件。通过对3根预应力混凝土管桩−承台机械连接试件进行足尺抗拔性能试验和数值模拟分析,研究了预应力混凝土管桩−承台机械连接的抗拔承载性能、变形延性及破坏形式。结果表明:预应力混凝土管桩−承台机械连接试件的极限抗拔承载力试验值均大于桩身极限抗拉承载力按规范规定的公式计算值;试件的破坏形式主要有3种,分别是桩身预应力钢棒被拉断、桩身上端板被拉脱和承台表面裂缝宽度过大。建立的有限元模型能较好地模拟试件从加载到破坏的全过程,数值模拟结果与试验结果吻合较好。通过参数分析可知:提高预应力混凝土管桩的预应力水平可以有效提高试件的开裂荷载,但会降低试件的变形延性;提高机械连接件锚固钢筋的竖直段长度可以有效降低锚固钢筋的应力水平,使预应力混凝土管桩与承台之间的锚固更加可靠。
In order to improve the construction quality and efficiency of the connection between precast concrete piles and pile caps,a mechanical connector used to connect prestressed concrete pipe piles and pile caps has been developed.The full-scale pull-out performance tests and numerical simulations were conducted on three prestressed concrete pipe pile-to-cap mechanical connection specimens to study the pull-out bearing capacity,deformation ductility and failure modes.The results show that the experimental values of the ultimate pull-out bearing capacity of the specimens are greater than the calculated values derived from the code formula for the ultimate tensile bearing capacity of the pile body.There are three main failure modes of the specimens:the tensile fracture of the prestressed steel bars in the pile body,pull-out of the upper end plate of the pile,and excessive crack width on the cap surface.The established finite element model can accurately simulate the whole process from loading to failure,and the numerical simulation results are in good agreement with the experimental results.Through parametric analysis,it can be concluded that increasing the prestressing level of prestressed concrete pipe piles can effectively improve the cracking load of the specimens,but reduces deformation ductility.Increasing the vertical length of the anchoring steel bars for mechanical connectors can effectively decrease the stress level of the anchoring steel bars,making the anchoring between prestressed concrete pipe pile and pile cap more reliable.
作者
李畅畅
陈刚
徐铨彪
王桂龙
龚顺风
LI Changchang;CHEN Gang;XU Quanbiao;WANG Guilong;GONG Shunfeng(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,Zhejiang,China;Center for Balance Architecture,Zhejiang University,Hangzhou 310028,Zhejiang,China;Jiangsu Hanlong Building Material Technology Co.,Ltd.,Xuzhou 221111,Jiangsu,China)
出处
《地基处理》
2025年第2期138-147,155,共11页
Journal of Ground Improvement
基金
浙江省重点研发计划资助项目(2018C03033-1)
住房和城乡建设部科技资助项目(2021-k-052)。
关键词
机械连接
预应力混凝土管桩
承台
抗拔性能
有限元分析
mechanical connection
prestressed concrete pipe pile
pile cap
pull-out performance
finite element analysis
作者简介
李畅畅(1999-),男,河南商丘人,硕士研究生,主要从事预制桩力学性能研究。E-mail:cchangli@126.com;通信作者:龚顺风(1975-),男,浙江杭州人,博士,教授,主要从事混凝土结构研究。E-mail:sfgong@zju.edu.cn。
