超高性能混凝土预应力锚固齿块承压性能研究  

Research on Local Pressure Performance of Ultra-high Performance Concrete Prestressed Anchor Block

作　　者：杨俊[1,2] 任伟 冷景晨 张中亚 邹杨[1,2] 周建庭[1,2] 胡天祥[3] YANG Jun;REN Wei;LENG Jingchen;ZHANG Zhongya;ZOU Yang;ZHOU Jianting;HU Tianxiang(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Shenzhen Expressway Group Co.,Ltd.,Shenzhen 518026,Guangdong,China)

机构地区：[1]重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆400074 [2]重庆交通大学土木工程学院,重庆400074 [3]深圳高速公路集团股份有限公司,广东深圳518026

出　　处：《材料导报》2023年第18期106-114,共9页Materials Reports

基　　金：国家自然科学基金(U20A20314,51908093);中国博士后科学基金(2021M693919);重庆市自然科学基金(cstc2020jcyj-msxmX0088);重庆交通大学研究生科研创新项目资助(2021S0017)。

摘　　要：为提高齿块的承压性能与耐久性能,以连续刚构桥预应力锚固齿块为研究对象,开展超高性能混凝土(UHPC)锚固齿块的承压性能试验,研究了局压与全压荷载作用下锚固齿块的抗裂性能、极限承载力、破坏特征和五种典型局部效应,并提出了UHPC预应力锚固齿块局压承载力计算公式。结果表明:UHPC能有效提高锚固齿块的抗裂性能和承压能力。相较于普通混凝土(NC)预应力锚固齿块,局压荷载作用下UHPC预应力锚固齿块的抗裂性能和极限承载能力分别提高了2.51倍和3.27倍,提升效果显著,在进行UHPC预应力锚固齿块设计时,在保证其力学性能并兼顾经济性的条件下,建议其尺寸设计为NC预应力锚固齿块的0.75倍。局部承压下,UHPC预应力锚固齿块的破坏模式与NC预应力锚固齿块存在明显区别,UHPC预应力锚固齿块的整体性更好,仅在底板和齿块出现微小裂缝,荷载-位移曲线具有明显屈服平台;同时,所有锚固齿块均呈现显著的“锚下劈裂效应”和“锚后牵拉效应”;最后,基于试验结果和有限元分析,对UHPC预应力锚固齿块局部区承载能力计算公式进行了修正,计算结果精度为95%,可为UHPC预应力锚固齿块的工程实际运用提供理论参考。In order to improve the pressure-bearing performance and durability of the prestressed anchor block,the prestressed anchor blocks of continuous rigid frame bridge were taken as research object and the compression performance test of the ultra-high performance concrete(UHPC)anchor blocks were carried out.The crack resistance,ultimate bearing capacity,failure characteristics and five typical local effects of the anchored tooth block under partial pressure and full pressure load were researched and the calculation formula of bearing capacity was proposed.The results show that UHPC can effectively improve the crack resistance and pressure-bearing capacity of the anchor tooth block.Compared with NC prestressed anchored tooth blocks,the crack resistance and ultimate bearing capacity of UHPC prestressed anchor blocks under local compressive load are increased by 2.51 times and 3.27 times,respectively.The improvement effect is remarkable.When designing the UHPC prestressed anchor tooth block,it is recommended that its size be designed to be 0.75 times the NC prestressed anchor tooth block under the condition of ensuring its mechanical properties and taking into account the economy.The local pressure-bearing failure mode of UHPC prestressed anchor block is obviously different from that of NC prestressed anchor block.Its integrity is better and only small cracks appear in the bottom plate and anchor block.The load-displacement curve has an obvious yield platform.At the same time,all prestressed anchor blocks show significant‘under-anchor splitting effect’and‘post-anchor pulling effect’.Finally,based on the test results and finite element analysis,the calculation formula for the local bearing capacity of UHPC prestressed anchor blocks is revised.The accuracy of the calculation result is 95%,which can provide a theoretical reference for the practical application of engineering in the future.

关 键 词：UHPC 预应力锚固齿块 局压承载能力 局部效应 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]