(1 湖南大学土木工程学院， 长沙 410012； 2 湖南大学工程结构损伤诊断湖南省重点实验室， 长沙 410012)

［摘要］已有研究表明，钢筋混凝土（RC）剪扭受力构件中，剪扭承载力存在相关性。我国《混凝土结构设计规范》（GBJ 10—89，GB 50010—2002和GB 50010—2010）基本沿用了相同的剪扭相关模型，即简化的三折线模型，这可能导致承载力局部计算结果偏于不安全。1/4圆弧曲线、直线、改进的三折线剪扭相关模型及对应的承载力计算公式被相继提出。在分析控制可靠指标β及其影响因素的基础上，提出规范及各修正公式对应的抗剪可靠指标和抗扭可靠指标存在一定程度的不平衡性，这种不平衡性取决于各公式相关模型对应的抗扭和抗剪承载降低系数。从配箍量、最低可靠指标和可靠指标的平衡性等角度，对规范及各修正公式进行了全面分析与比较。

［关键词］RC剪扭构件；相关性；修正公式；可靠指标；平衡性

中图分类号：TU375文献标识码：A文章编号：1002-848X(2019)02-0055-09

Reliability research on bearing capacity formula of RC  shear and torsion members

Zhang Wangxi1,2, Li Bo1, Deng Xi1, Xiao Longjie1, Liu Jingjin1, Han Jiang1

(1 Civil Engineering College, Hunan University, Changsha 410012, China；2 Hunan Provincial Key Lab on Diagnosis for Engineering Structures,  Hunan University, Changsha 410012, China)

Abstract:The research results indicate that there exists correlation between shear capacity and torsion capacity in the RC shear and torsion members. In China, Code for design of concrete structures（GBJ 10—89, GB 50010—2002 and GB 50010—2010）, always carry out the same shear and torsion correlation model, that is simplified trilinear model. This model may cause the bearing capacity calculation results to unsafe state sometimes. The models based on the 1/4 circular arcs, straight line and modified trilinear, as well the corresponding formula for calculating bearing capacity were put forward one after another. Based on the analysis of control reliability index β and its affecting factors, the unbalance of shear and torsion reliability index according to different formulas was pointed out. This unbalance depends on the reducing coefficient of shear and torsion bearing capacity that is corresponding to the formula for different model. From the point of strip steel, minimum reliability index and the balance of reliability index, the code and modified formula were analyzed fully and compared with each other.

Keywords:RC shear torsion member; correlation; modified formula; reliability index; balance

*国家自然科学基金资助项目（51578228，51338004）,国家重点专项(2016YFC0701400)。

作者简介：张望喜，博士，副教授，Email：wxizhang2000@hnu.edu.cn。