大悬臂预应力节段预制拼装盖梁抗弯性能研究  

Research on bending resistance of prefabricated and assembled cap beams with large cantilever prestressed segments

作　　者：霍龙飞 方春平 姚晓飞[1] 刘浩 刘胜玉 HUO Longfei;FANG Chunping;YAO Xiaofei;LIU Hao;LIU Shengyu(CCCC First Highway Consultants Co.,Ltd.,Xi′an 710065,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710065

出　　处：《混凝土》2024年第10期137-143,共7页Concrete

基　　金：国家重点研发计划(2021YFB2600404)。

摘　　要：为研究平缝、阶梯缝预应力节段拼装盖梁的抗弯力学性能,设计制作了一组预应力节段拼接盖梁抗弯试件,一端悬臂为平缝拼装试件,另一端为阶梯缝拼装试件,一组现浇对比试件。通过开展静力加载试验,对比两种拼接方案与现浇试件的破坏模式、荷载-位移曲线特征。基于试验分析结果,建立两种拼接方案与现浇试件有限元分析模型,与试验结果吻合较好,基于此开展预应力钢束面积、普通钢筋直径对结构极限承载力的影响参数分析。研究结果表明:相同配筋率下,节段式施工对构件抗弯承载力有一定削弱效应,本试验中相比现浇盖梁试件,节段拼装盖梁试件抗弯承载力仅为其40%;基于有限元参数分析可知,通过减小普通钢筋配制、增加预应力钢束的占比,并对拼接面附近做局部加强设计可提高节段拼装盖梁极限承载力。基于上述结果,可对预应力节段拼装盖梁的设计和应用提供参考。In order to study the bending mechanical properties of pre-stressed segmental assembled cap beams with flat and stepped joints,a set of pre-stressed segmental assembled cover beam bending test specimens was designed and manufactured.One end of the cantilever was used as a flat joint assembly test specimen,the other end was used as a stepped joint assembly test specimen,and a set of cast-in-place comparative test specimens was designed and manufactured.By conducting static loading tests,the failure modes and load-displacement curve characteristics of two splicing schemes and cast-in-place specimens were compared.Based on the experimental analysis results,two splicing schemes and a finite element analysis model of cast-in-place specimens were established,which were in good agreement with the experimental results.Based on this,the parameter analysis of the influence of prestressed steel tendon area and ordinary steel bar diameter on the ultimate bearing capacity of the structure was carried out.The research results indicate that under the same reinforcement ratio,segmental construction has a certain weakening effect on the bending bearing capacity of the components.In this experiment,compared to the cast-in-place cover beam specimens,the bending bearing capacity of the segmented assembled cover beam specimens is only about 40%of that;Based on finite element parameter analysis,it can be seen that reducing the configuration of ordinary steel bars,increasing the proportion of prestressed steel tendons,and locally strengthening the design near the splicing surface can improve the ultimate bearing capacity of the segmental assembly cover beam.Based on the above results,it can provide reference for the design and application of pre-stressed segmental assembly cap beams.

关 键 词：城市桥梁 抗弯性能 试验研究 数值计算 节段拼装盖梁 

分 类 号：TU528.7[建筑科学—建筑技术科学]