（1 湖南大学土木工程学院， 长沙 410082; 2 工程结构损伤诊断湖南省重点实验室， 长沙 410082）

［摘要］进行了16根钢筋混凝土无腹筋变截面悬臂梁试件集中荷载静力试验，实时量测了纵筋应变、受压区混凝土应变和挠度，记录了裂缝开展过程和破坏形态。结果表明，梁受剪承载力与受压边倾角、纵筋配筋率和悬挑端截面有效高度有明显正相关性；受压边倾角越大，变截面梁受剪破坏截面的位置越靠近悬挑端。非线性有限元分析表明变截面梁抗剪机制可用拱效应解释。基于试验分析及37个试验数据的统计分析，提出了反映受压边倾角对拱效应影响的系数以及确定验算截面位置的方法，建立了与中国规范公式衔接的变截面梁受剪承载力计算公式。

［关键词］变截面梁； 受剪承载力； 拱效应

中图分类号：TU317-2,  TU375文献标识码：A文章编号：1002-848X(2018)02-0007-07

Experimental study on shear strength of haunched  reinforced concrete  cantilever beams without transverse reinforcement

Yu Dong1,2, Yi Weijian1,2

(1 College of Civil Engineering, Hunan University, Changsha 410082, China; 2 Engineering Structures Damage Diagnosis Key Laboratory of Hunan Province, Changsha 410082, China)

Abstract:Sixteen haunched reinforced concrete beams without transverse reinforcement were tested under concentrated load. Strain of longitudinal bars, strain of concrete in compression zone and deflection were measured, patterns of cracks and  failure mode of the specimens were recorded. Test results show that shear capacity is positively correlated with the inclined angle of haunch, longitudinal reinforcement ratio and the effecitve height of cantiliever beam end;  the larger the inclined angle of hauch is, the closer the cross section of the shear failure position is to the cantilever end. The nonlinear finite element analysis  indicated that the shear mechanism of hauched beams can be explained by arch  section. Based on analysis of tests and statistically analyzing 37 test results, a parameter considering the influence of inclined angle of haunch to arch action and a method of choosing the critical section were introduced. A new shear strength formula for haunched reinforced concrete beams was proposed which connect with Chinese code.

Keywords:haunched beam; shear capacity; arch action

*国家重点研发计划重点专项（2016YFC0701400）,国家自然科学基金项目（51338004）。

作者简介：余东，硕士，高级工程师，Email:nil_yu@126.com。