剪扭复合作用下预制拼装混凝土桥干接缝抗剪强度分析  

Shear Strength of Dry Joints in Precast Concrete Segmental Bridges under Shear-torsion Interaction

作　　者：王海良 李搏瀚 WANG Haiiang;LI Bohan(School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;National and Local Joint Engineering Research Center for Resource Utilization Technology of Construction Solid Wastes,Tianjin 300384,China;Tianjin Urban Construction Design Institute Co.,Ltd.,Tianjin 300122,China)

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]建筑固体废弃物资源化利用技术国家地方联合工程研究中心,天津300384 [3]天津城建设计院有限公司,天津300122

出　　处：《防灾减灾工程学报》2023年第4期818-825,853,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：天津市科委轨道交通重大专项课题(18ZXGDGX00050)资助。

摘　　要：为研究剪扭复合作用对单键齿干接缝抗剪强度影响,本文结合实际预制拼装混凝土桥剪力键尺寸与形状,利用ABAQUS有限元软件对干接缝剪力键受剪扭复合作用直至失效过程进行分析;研究过程首先以已有学者剪力键纯剪切试验为对象,建立其有限元模型,对比文献可以得出:数值模拟与试验得到的接缝位置抗剪强度比值平均为0.94,且数值模拟中裂缝位置与试验裂缝出现位置较为接近,裂缝演化过程较好吻合;在此基础上采用相同方法建立新数值模型,并通过改变荷载作用位置对剪力键施加剪扭复合作用,结果表明:单键齿干接缝抗剪强度随荷载所产生扭转作用增大而减小,扭转对剪力键抗剪强度降低幅度影响显著,当键齿厚度为400 mm,荷载偏移距离为275 mm,荷载移动距离为键齿厚度1/1.45时,抗剪强度较受纯剪切荷载模型减少超过40%;对60个剪扭复合作用模型抗剪强度降低值线性回归,得到偏载距S与抗剪强度减少系数P之间关系为P=1.758×10^(-3)S-0.042,依此对美国AASHTO规范中干接缝抗剪承载力预测计算式提出修改建议;通过另建立8个设置不同参数的剪扭复合作用模型验证修正后计算式准确性与一般性,数值模拟与修正计算式得到的抗剪强度比值平均为1.01,最大为1.06。In order to analyze the effect of shear-torsion interaction on the shear strength of singlekeyed dry joints,a model of shear-torsion combined action of keyed dry joints was established based on ABAQUS finite element software.Firstly,some finite element models of pure shear tests of shear keys were established to prove the reliability of the modeling method.The results showed that the ratio of shear strength between the numerical simulation and the experiment was 0.94,the cracks locations of the simulation were close to those of experimental results,and the evolution of cracks was in good agreement.On this basis,a new numerical model was established by the same method,and the shear-torsion composite effect was exerted on these shear keys by changing the load position.The results showed that the shear strength of single-keyed dry joints decreased with the increase of torsion,and torsion had a significant effect on the shear strength reduction.When the thickness of the key was 400mm,the load offset distance was 275mm,and the load movement distance versus the thickness of the key was 1/1.45,shear strength was reduced by more than 40%compared with pure shear models.After linear regression on 60 shear-torsion composite models,the relationship between shear strength reduction factor P and offset load distance S was P=1.758×10^(-3)S-0.042,and accordingly,a modification proposal was proposed for the prediction formula of shear capacity of dry joints in AASHTO.Eight shear-torsion composite models with different parameters were established to verify the accuracy and generality of the revised formula,and the ratio of shear strength obtained by numerical simulation and the modified formula was 1.01 on average and 1.06 on maximum.

关 键 词：剪扭复合作用 预制混凝土节段桥梁 抗剪强度 数值模拟 干接缝 剪切破坏 

分 类 号：U441[建筑科学—桥梁与隧道工程]