黄远 尹文萌 易伟建

摘要：为了研究钢筋混凝土牛腿的抗剪承载力，并评估我国和欧美规范牛腿设计方法的准确性和安全性，基于收集的209组牛腿竖向受剪试验数据对ACI 318-19、EC2、CSA A23.3-04和其他主要的牛腿抗剪承载力计算方法进行评估，发现欧美规范拉压杆模型方法较为保守，而软化拉压杆模型（softened strut-and-tie model，SSTM）能够较好地预测牛腿的抗剪承载力.在此基础上，设计了一系列满足我国规范要求的钢筋混凝土牛腿，主要变化的参数包括剪切跨度、混凝土强度、钢筋强度等，通过将牛腿的设计剪力与软化拉压杆模型计算得到的抗剪承载力进行对比，分析了不同设计参数下我国规范方法的准确性和安全性.并根据参数分析结果拟合了牛腿承载力修正系数的简化公式，并通过试验数据验证了简化公式的准确性和合理性.最后对牛腿在剪力作用下的设计方法提出了改进建议，可供钢筋混凝土牛腿设计参考.

关键词：钢筋混凝土牛腿；软化拉压杆模型；抗剪承载力；参数分析；结构设计

中图分类号：TU375文献标志码：A

基金项目：国家重点研发计划项目（2018YFC0705700），National Key Research and Development Project（2018YFC0705700）；国家自然科学基金资助项目（51890901），National Natural Science Foundation of China（51890901）

Study on Design Modification Factor for Shear Capacity of Reinforced Concrete Corbels

HUANG Yuan1，2，YIN Wenmeng2，YI Wenjian1，2

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

Abstract：In order to study the shear capacity of reinforced concrete corbels，and evaluate the accuracy and safe-ty of the design method of Chinese and abroad code，based on the collected test data of 209 corbels，the shear capacity formulas of ACI 318-19，EC2，CSA A23.3-04 as well as the main strut-and-tie models were evaluated. It was found that the calculation results of abroad code are too conservative，while the softened strut-and-tie model（SSTM）can better predict the shear capacity of corbel. On this basis，a series of reinforced concrete corbels were designed accord-ing to the Chinese code with various parameters including shear span，concrete strength，reinforcement strength，etc. By comparing the designed shear capacity with the calculation results of the softened strut-and-tie model，the accura-cy and safety of Chinese code under different design parameters were analyzed. Then，the simplified formula of the modification factor of the corbel bearing capacity was proposed. Based on the collected test data，the simplified for-mula was proved to be accurate. Design suggestions were proposed for the corbels under shear load，which can be used as a reference for the design of reinforced concrete corbels.

Key words：reinforced concrete corbels；softened strut-and-tie model；shear capacity；parameter analysis；struc-tural design

鋼筋混凝土牛腿被广泛应用于装配式混凝土结构中预制构件之间的铰接连接[1].例如工业厂房的预制混凝土柱牛腿，用于支承吊车梁、屋架及墙梁等水平构件.牛腿用于构件连接其施工非常便捷，但是在荷载作用下，牛腿的受力状态较为复杂，类似于变截面深梁，在国际上通常将钢……