桥墩盖梁预应力装配式混凝土挡块抗震性能研究  

Research on seismic performance of the prestressed prefabricated concrete retaining blocks on bridge cap beams

作　　者：吴文朋[1] 王喜鹏 张红运 WU Wenpeng;WANG Xipeng;ZHANG Hongyun(College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105

出　　处：《地震工程与工程振动》2022年第3期104-112,共9页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51908481);湖南省自然科学基金项目(2020JJ5543);中国博士后科学基金面上项目(2018M640756)。

摘　　要：针对传统整体式挡块遭受地震破坏以后修复较困难的问题,提出一种适用于桥墩盖梁的可替换式预应力装配式混凝土挡块。为探讨新挡块在水平地震荷载作用下的有效性和力学性能,共设计了4组结构名义尺寸相同的抗震挡块试件,其中,S1和S2为整体式挡块,S3和S4为榫卯装配式挡块,分别对4组试件进行单向往复拟静力加载试验,分析挡块材料和结构形式对挡块破坏模式的影响;最后,结合有限元分析讨论了榫卯装配式挡块的破坏机理和存在的不足,并给出进一步的改进建议。研究结果表明:整体式普通混凝土(NC)挡块的破坏模式为典型的斜剪破坏;整体式超高性能混凝土(UHPC)挡块的破坏模式为水平钢筋逐层断裂的界面破坏,UHPC挡块本身损伤较小且承载能力远高于NC挡块;预应力装配式NC挡块的水平位移能力和自复位能力较好,但最终破坏模式仍为剪切破坏且承载能力有所降低;经过进一步改进后的直缝装配式UHPC挡块能同时满足较大的水平承载能力、位移能力和自复位功能的需求,建议可作为我国中小跨径桥梁桥墩盖梁处横向挡块抗震设计或加固的有益补充形式。Due to the difficulty to repair the traditional monolithic seismic retaining block after it was damaged in earthquake event,this paper proposed a prestressed and prefabricated concrete retaining block which is applicable to the bridge cap beams.In order to study the anti-seismic effectiveness and basic mechanical properties of the new retaining block under the lateral seismic loads,four retaining block specimens with nominally identical sizes were designed.S1 and S2 are the traditional monolithic blocks,S3 and S4 are the new prefabricated blocks.The quasi-static tests under monodirectional and cyclical loads were carried out on four specimens respectively.The influence of the structural material and forms on seismic damage mode of the anti-seismic retaining blocks were investigated.Finally,the failure mechanism and shortcomings of the prefabricated retaining block with mortise and tenon are discussed based on finite element analysis,and suggestions for further improvement are given.It is concluded that,the failure mode of the monolithic normal concrete(NC)retaining block is typical diagonal shear failure.The failure mode of monolithic ultra-high-performance-concrete(UHPC)retaining block is the interface damage due to yield and broken of the horizontal steels layer by layer.The damage of UHPC retaining block itself is limited,but its bearing capacity is much higher than that of the monolithic NC retaining block.The lateral displacement and self-resetting capacity of prestressed and prefabricated NC retaining block performs well,but its final damage mode is still the shear failure and its bearing capacity is less than that of monolithic NC retaining block.However,the modified prefabricated UHPC retaining block can simultaneously satisfy the requirements of higher lateral bearing capacity,displacement capacity and self-resetting capacity.Therefore,it is suggested as a useful supplement for seismic design and retrofitting of the retaining block on pier cap beams in the mediumsmall span bridges in China.

关 键 词：桥梁工程 挡块 试验研究 装配式结构 有限元分析 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]