研究目的:目前,国内外桥梁抗震设计规范普遍采用基于墩底截面弯矩—曲率分析和塑性铰模型的变形能力分析方法来定量计算桥墩在水平地震下的延性能力,为了考察这种分析方法在我国铁路桥墩抗震设计中的适用性,对当前尚缺少研究的圆端形铁路桥墩的变形能力进行理论分析和试验验证。
研究结论:(1)圆端形桥墩试件变形能力的理论计算结果与试验结果非常吻合,基于墩底截面弯矩一曲率分析和塑性铰模型的变形能力分析方法适用于圆端形铁路桥墩的抗震设计;(2)圆端形铁路桥墩的等效塑性铰长度经验公式和塑性铰区最大容许转角的延性安全系数的取值可以与我国JTG/T B02—01细则和CJJ166规范的规定相一致;(3)本文给出的圆端形桥墩变形能力分析方法为我国铁路桥梁圆端形桥墩的延性抗震设计提供了方法和依据。
Research purposes:At present,the deformation capacity analysis method based on the moment-curvature analysis of the bottom cross-section and the plastic hinge models is widely used in the domestic and foreign seismic design codes for bridges to quantify the ductility ability of piers under horizontal seismic load.In order to investigate the applicability of this analysis method to the seismic design of railway bridge piers in China,the theoretical analysis and experimental verification of the deformation capacity of the round-ended railway bridge piers which is still lack of research currently are executed.
Research conclusions:(1)The theoretical calculation results of the deformation capacity of the round—ended pier specimens correspond with the test results very well,and the deformation capacity analysis method based on the moment curvature analysis of the bottom cross-section and the plastic hinge models can be applied to the seismic design of the round—ended railway bridge piers.(2)The empirical formula of equivalent plastic hinge length and the ductility safety factor of the maximum permissible angle of the plastic hinge of the round-ended railway bridge piers can be same with the Chinese code JTG/T B02-01 and CJJ 166.(3)The deformation capacity analysis method of round—ended piers presented provides a practical method and basis for seismic ductility design of the round-ended railway bridge piers in China.