弯矩和剪力组合作用下混凝土梁截面抗剪计算理论研究  

Theoretical Study of Shear Capacity Calculation of Concrete Girder Under Combined Bending and Shear Effects

作　　者：胡可 刘畅[2] 端木祥永 王胜斌[3] HU Ke;LIU Chang;DUANMU Xiangyong;WANG Shengbin(Anhui Transportation Holding Group Co.,Ltd.,Hefei 230092,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Anhui Transport Consulting&Design Institute Co.,Ltd.,Hefei 230088,China)

机构地区：[1]安徽省交通控股集团有限公司,安徽合肥230092 [2]同济大学土木工程学院,上海200092 [3]安徽省交通规划设计研究总院股份有限公司,安徽合肥230088

出　　处：《桥梁建设》2023年第6期135-141,共7页Bridge Construction

基　　金：国家自然科学基金面上项目(52078363);安徽省交通控股集团科技项目(JKKJ-2020-40)。

摘　　要：为准确计算钢筋混凝土梁及预应力钢筋混凝土梁在弯矩和剪力组合作用下的截面抗剪承载力,进行钢筋混凝土梁及预应力钢筋混凝土梁截面抗剪计算理论研究。根据混凝土梁抗剪破坏特征,考虑混凝土、纵向钢筋、竖向箍筋、弯起钢筋以及预应力筋对梁抗剪性能的影响,提出一种基于楔形截面的抗剪计算模型,并对抗剪承载力的上限值和下限值进行分析。开展轻型T梁计算和足尺模型静载试验,并进行对比验证。结果表明:楔形截面抗剪计算模型解释了混凝土梁纵向钢筋、竖向箍筋、弯起钢筋的抗剪承载力贡献,并为抗剪承载力的设计提供了实用的公式;该模型的抗剪上限值为最小腹板厚度提供了理论解释,即纵向钢筋、竖向箍筋均存在一个充分配筋率下的腹板厚度;通过实例计算和足尺模型静载试验,楔形截面抗剪计算模型和计算方法相对于传统方法更为准确和合理,具有更好的理论基础。This research aims to accurately determine the shear capacity of reinforced concrete(RC)and prestressed concrete(PC)beams under combined bending and shear effects.The research is based on the theoretical calculation of shear resistance for both RC and PC beams.It takes into consideration the failure characteristics of structural members and the influence of concrete,longitudinal reinforcement,vertical stirrups,bent-up bars,and prestressing tendons on shear performance.A shear calculation model based on a wedge-shaped section is proposed,and both the upper and lower limits of shear capacity are analyzed.Lightweight T-beam calculations and full-scale static loading tests were conducted,and results are compared for validation.The findings reveal that the wedge-shaped shear model explains the shear capacity contribution components of concrete beams,providing practical formulas for shear capacity design.The upper limit of this model offers a theoretical explanation for the minimum web thickness,taking into account a sufficient reinforcement ratio for longitudinal reinforcement and vertical stirrups.Through example calculations and full-scale tests,the wedge-shaped shear model and its calculation method demonstrate greater accuracy and rationality compared to traditional approaches,offering a stronger theoretical foundation.

关 键 词：桥梁工程 混凝土梁 楔形截面抗剪计算模型 抗剪承载力 最小腹板厚度 静载试验 

分 类 号：U448.33[建筑科学—桥梁与隧道工程] U441.4[交通运输工程—道路与铁道工程]