剪扭复合作用下节段预制拼装桥干接缝剪力键抗剪性能试验研究  

Experimental Study on Shear Behavior of Single-Keyed Dry Joint of Precast Concrete Segmental Bridge under Combined Shear and Torsion

作　　者：王海良 李搏瀚 郭晓宇 姜金垚 黄欣[3] WANG Hai-liang;LI Bo-han;GUO Xiao-yu;JIANG Jin-yao;HUANG Xin(School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,Tianjin 300384,China;China Railway 18th Bureau Group Co.,Ltd.,Tianjin 300222,China)

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]天津市土木建筑结构防护与加固重点实验室,天津300384 [3]中铁十八局集团有限公司,天津300222

出　　处：《桥梁建设》2022年第2期31-38,共8页Bridge Construction

基　　金：天津市轨道交通重大专项项目(18ZXGDGX00050);天津市教委科研计划项目(2020KJ038)。

摘　　要：为研究剪扭复合作用对干接缝单键齿剪力键抗剪性能的影响,考虑偏载距、正应力水平以及键齿宽高比3种影响因素,设计、制作10组干接缝单键齿剪力键试件进行纯剪试验及剪扭复合试验,分析试件的开裂荷载、极限荷载及破坏形态等。结果表明:干接缝单键齿剪力键抗剪强度随扭矩增大而减小,与受纯剪作用试件相比,当偏载距分别为100 mm和200 mm(剪力键键齿厚度的1/4和1/2)时,开裂荷载分别减少25.13%和37.01%,极限荷载分别减少18.12%和26.45%;正应力增大时,试件开裂荷载与极限荷载均有所增加;不同键齿宽高比对极限承载力无明显影响。纯剪作用下键齿破坏时整体从根部被剪断,剪扭复合作用下键齿只有偏载侧部分破坏脱落。通过对比试验值与现有文献和规范中公式计算值发现,偏载距为键齿厚度的1/2时,试验值与计算值之比的平均值为0.61~0.76,建议现有计算公式中应考虑偏载距影响。In this study,10 pairs of specimens with single-keyed dry joints were prepared for pure shear tests and combined shear and torsion tests,which took into account the three influential factors of offset distance,normal stress level and width-to-depth ratio of shear keys,aiming to investigate the combined shear and torsion effect on the shear capacity of the single shear key.The cracking load,ultimate load and failure modes of the specimens were analyzed.The results show that the increase of torsion can result in the decrease of shear capacity of the shear key.Compared to the specimens applied with pure shear forces,when the offset distances were set at 100 mm and 200 mm,namely 1/4 and 1/2 of the depth of the shear key,the cracking load can be reduced by 25.13%and 37.01%,and ultimate load reduced by 18.12%and 26.45%,respectively.As the normal stress increased,the cracking load and ultimate load of the specimen showed sign of increasing.The width-to-depth ratio of shear key had no obvious effect on the ultimate load bearing capacity of the specimen.When destroyed by pure shear forces,the shear key was cut off at the root,while under the combined shear and torsion effect,only the part of the shear key bearing eccentric loads was damaged and stripped off.The test results were compared with the literature and calculations by the formulas in current codes,and it is shown that when the offset distance is half of the shear key depth,the ratio of average calculated results and test results is between 0.61 and 0.76.It is suggested that the offset distance be considered in the current calculation formulas.

关 键 词：节段预制拼装桥 干接缝 剪力键 剪扭复合作用 抗剪承载力 破坏形态 纯剪试验 剪扭复合试验 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]