深受弯盖梁计算方法及设计要点分析  

Analysis of Calculation Method and Design Points of Deep Bent Capping Beam

作　　者：卫德刚 Wei Degang(Beijing Guodaotong Highway Design&Research Institute Co.,Ltd.,Beijing 100073,China)

机构地区：[1]北京国道通公路设计研究院股份有限公司,北京100073

出　　处：《市政技术》2023年第4期38-43,56,共7页Journal of Municipal Technology

摘　　要：在结构设计中,当梁跨高比l/h≤5.0时称为深受弯构件(包括短梁和深梁),在外荷载作用下,深受弯构件截面应变不符合平截面假定,承载力计算原理与一般受弯构件不同。在桥梁设计领域,柱式墩台盖梁以及桩基承台均属于转换梁,具有跨径小、截面高度大的特点,跨高比一般不大,普遍属于深受弯构件。根据相关规范规定,盖梁跨中跨高比为2.5<l/h≤5.0时采用内力臂表达式计算正截面抗弯承载力,盖梁外悬臂集中力作用点距柱外边缘的距离小于或等于盖梁截面高度时,按拉压杆模型计算。结合某城市快速路钢筋混凝土盖梁设计实例,论述了深受弯盖梁承载力计算方法,并与采用一般受弯梁计算承载力计算结果进行了比较,揭示了深受弯盖梁的受力特点和设计要点,为类似工程提供了参考。In the structural design,when the beam span height ratio l/h ≤5.0,it is called deeply bending member(including short beam and deep beam).Under the action of external load,the section strain of deeply bending member does not conform to the assumption of flat section,and the calculation principle of bearing capacity is different from that of general bending member.In the field of bridge design,both the column pier cover beam and pile cap are the conversion beam with the characteristics of small span,large section height and span height ratio is generally not big which belong to the bending member.According to the relevant regulations,when the ratio of span span to height of the cover beam is 2.5<l/h≤5.0,the flexural capacity of the normal section is calculated by the internal moment arm expression.When the distance between the concentrated force point of the outer cantilever of the cover beam and the outer edge of the column is less than or equal to the height of the cover beam section,the flexural capacity is calculated as the tensile rod model.Combined with the design example of reinforced concrete covered beam of an urban expressway,the calculation method of bearing capacity of heavily bent covered beam is discussed.The calculation result is compared with that of general bent beam.The stress characteristics and design points of heavily bent covered beam are revealed which can provide reference for similar projects.

关 键 词：盖梁 深受弯构件 计算方法 设计要点 承载力 

分 类 号：U448.34[建筑科学—桥梁与隧道工程]