摘要
预应力高强混凝土(PHC)管桩因其高承载力和高经济效益被广泛应用,但是存在脆性破坏问题。加筋型预应力高强混凝土(PHCR)管桩的提出有助于改善上述问题。为了研究不同桩型在水平往复荷载作用下的抗震性能,通过2根PHC管桩和2根PHCR管桩的现场足尺试验,对比了各管桩的试验现象和破坏模式,分析了骨架曲线、各阶段水平承载力、位移延性系数、刚度退化曲线以及钢筋应变发展等。结果表明:增加预应力钢筋配筋率提高了桩身初始刚度,显著提高了管桩的水平承载力,而增置非预应力钢筋延缓了预应力钢筋的屈服与刚度退化,大幅提高了管桩的延性,减少了脆性破坏的风险。在此基础上,使用ABAQUS建立了管桩-土体三维有限元模型,进一步研究预应力钢筋配筋率和非预应力钢筋配筋率对预应力管桩抗震性能的影响。分析得出在不同预应力钢筋配筋率条件下,均存在对应的最优非预应力钢筋配筋率,即当两种钢筋配筋率比值接近1时,可以在保证水平承载力的同时最大程度提高管桩变形能力。
Prestressed high-strength concrete(PHC)piles are widely used due to their high load-bearing capacity and economic benefits,but they are prone to brittle failure.The introduction of prestressed high-strength concrete reinforced with non-prestressed tendons(PHCR)piles helps to address these issues.Field tests consisting of two PHC piles and two PHCR piles in full size were conducted to investigate the seismic performance of different pile types by comparing the experimental phenomena and failure modes of each specimen.Under horizontal cyclic loading,the skeleton curves,horizontal loads at different stages,displacement ductility,stiffness degradation,and reinforcement strain were examined.The results indicate that increasing the prestressed steel reinforcement ratio improves the initial stiffness of the pile and significantly enhances the maximum horizontal load.Meanwhile,adding non-prestressed steel reinforcement delays the yielding and stiffness degradation of the prestressed steel,greatly enhances the ductility of the pile,and reduces the brittle failure risk.On this basis,a three-dimensional pile-andsoil finite element model was established using ABAQUS to further examine the effects of prestressed reinforcement ratios(PRs)and non-prestressed reinforcement ratios(NPRs)on seismic performance of PHC and PHCR piles.Analysis reveals an optimal NPR for each PR.When the ratio of two bar ratios is close to 1,the deformation capablity of the prestressed pile can be maximally enhanced while ensuring the horizontal bearing capacity.
作者
郑刚
闫城东
刘畅
赵博
刘永超
ZHENG Gang;YAN Chengdong;LIU Chang;ZHAO Bo;LIU Yongchao(School of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education,Tianjin University,Tianjin 300072,China;Tianjin Construction Inheritance Group Limited Company,Tianjin 300301,China)
出处
《建筑结构学报》
北大核心
2025年第8期229-242,共14页
Journal of Building Structures
基金
国家自然科学基金项目(52078335,52278406)。
关键词
预应力高强混凝土管桩
非预应力钢筋
现场试验
有限元分析
抗震性能
prestressed high-strength concrete(PHC)pipe pile
non-prestressed reinforcement
field test
finite element analysis
seismic performance
