超高强混凝土混合配筋管桩受弯承载性能研究  

Study on Flexural Bearing Capacity of Ultra⁃high Strength Concrete Mixed Reinforced Pipe Pile

作　　者：常欢欢 CHANG Huanhuan(Henan Construction Group Co.,Ltd.,Zhengzhou,Henan450000,China)

机构地区：[1]河南省建设集团有限公司,河南郑州450000

出　　处：《施工技术（中英文）》2024年第22期29-36,共8页Construction Technology

基　　金：河南省重点研发与推广项目(2022102320129);河南省住房和城乡建设科学技术计划(HNJS-2022-K17)。

摘　　要：为研究超高强混凝土(C105)混合配筋管桩的抗弯承载性能,对设计制作的6根混凝土管桩进行抗弯性能试验,分析非预应力钢筋配置对超高强混凝土管桩受弯性能的影响。试验结果表明:PRC管桩和PHC管桩试件均呈现受弯破坏,前者破坏时表现出更明显的延性破坏状态;非预应力钢筋的配置,改善了管桩桩身裂缝分布情况,其裂缝数量随非预应力钢筋配筋率的提高而增多,平均裂缝间距则逐渐减小。相同荷载下的最大裂缝宽度亦随非预应力钢筋配筋率的提高而减小。与试验结果相比,现行图集抗弯承载力计算值偏小,对于延性较好的PRC管桩而言,安全储备过高;且相关计算参数多为经验参数,缺乏一定的理论依据。因此,考虑C105级混凝土及受拉区预应力钢筋合力取值对管桩抗弯承载力的影响,基于相关计算假定,对图集抗弯承载力公式进行修正。计算结果表明修正后计算公式较现行图集的计算结果提高了5%~10%。In order to study the flexural bearing capacity of ultra-high strength concrete(C105)mixed reinforced pipe piles,the flexural performance test of six concrete pipe piles was carried out,and the influence of non-prestressed reinforcement configuration on the flexural performance of ultra-high strength concrete pipe piles was analyzed.The test results show that both PRC pipe pile and PHC pipe pile specimens show flexural failure,and the former shows more obvious ductile failure state when it is destroyed.The configuration of non-prestressed steel bars improves the distribution of cracks in the pipe pile.The number of cracks increases with the increase of the reinforcement ratio of non-prestressed steel bars,and the average crack spacing decreases gradually.The maximum crack width under the same load also decreases with the increase of non-prestressed reinforcement ratio.Compared with the test results,the calculated value of the flexural bearing capacity of the current atlas is small,and the safety reserve is too high for the PRC pipe pile with good ductility.And the relevant calculation parameters are mostly empirical parameters,lacking a certain theoretical basis.Therefore,considering the influence of the resultant force of C105 concrete and prestressed reinforcement in tension zone on the bending capacity of pipe piles,the formula of bending capacity of the atlas is modified based on the relevant calculation assumptions.The calculation results show that the modified calculation formula is 5%~10%higher than the calculation results of the current atlas.

关 键 词：超高强混凝土 预制混凝土管桩 混合配筋 受弯性能 试验 

分 类 号：TU37[建筑科学—结构工程]