【摘要】 为了研究钢筋混凝土桥墩的延性配箍要求,总结了中、美、欧主要桥梁抗震设计规范对延性桥墩塑性铰区最低约束箍筋用量的规定,结合美国PEER柱抗震性能试验数据库、日本Kawashima实验室和部分中国的试验数据,整理了234根桥墩的拟静力试验数据;建立了桥墩极限位移角与位移延性系数、曲率延性系数的对应关系,讨论了中、美、欧主要桥梁抗震设计规范约束箍筋用量及构造措施对保证桥墩延性的可靠性;在此基础上分别以2%和3%极限位移角为延性目标,通过回归分析建立了具有85%保证率的桥墩塑性铰区约束箍筋用量计算公式;通过一个设计实例将建议公式与各国规范进行了对比。结果表明:该公式适用于剪跨比在3～10范围内的普通及高强混凝土桥墩,既可保证高轴压下桥墩延性抗震能力,又可保证低轴压下配箍要求不过于保守。更多还原

【Abstract】 In order to study the confining reinforcement requirement for ductile RC bridge columns,the code provisions of confining reinforcement in the potential plastic hinge regions of bridge columns in China,USA and Europe were summarized.Then,234 pseudo-static test data for bridge columns were collected from Pacific Earthquake Engineering Research Center(PEER) column database,Kawashima Laboratory and other literatures in China.The relationships between the ultimate drift ratios and displacement ductility factors and curvature ductility factors of the columns were developed.The code provisions for the amount of confining reinforcement in bridge columns in China,USA and Europe were evaluated.Then,calculated equations of amount of confining reinforcement required to achieve a given ultimate drift ratios of 2% and 3% with 85% assurance rate were proposed based on regression analysis.Through a practical example,comparisons of equations in the paper and code at home and abroad were carried out.Results show that the proposed equations can be used for the bridge columns with aspect ratio 3 to 10 and can keep good seismic capacity for the columns under high axial load ratio but is not very conservative for the columns under low axial load ratio.更多还原