考虑高阶振型的改进能力谱法在铁路高桥墩中的应用

以我国《铁路工程抗震设计规范》为依据，在前人建议的模态分析Pushover法的基础上，针对我国大跨铁路桥梁中的高桥墩，提出能考虑高阶振型影响的改进能力谱法，并以内昆线花土坡铁路特大桥8#墩为实例，验证了改进方法评估高桥墩抗震性能的合理性，得到如下结论：①提出能考虑高阶振型的公式，使模态分析Pushover法能更好地考虑高阶振型的影响；②选取四类场地320条强震记录，统计了与我国《铁路工程抗震设计规范》相应的强度折减系数谱和弹塑性需求谱，为改进方法提供设计谱；②以墩高110m的 8#墩为例，验证了考虑高阶振型的改进能力谱法应用于桥梁抗震性能评估的合理性。综上所述，研究成果可为同类工程抗震性能的研究提供有益参考。

Application of improved capacity spectrum method considering high-order mode to tall pier of railway bridge

Based on the Code of Seismic Design for Railway Engineering and the modal Pushover analysis, an improved capacity spectrum method with high-order mode considered was proposed for the tall piers of large-span railway bridges. Furthermore, the rationality of the improved capacity spectrum method was validated based on the 8# tall pier of Huatupo railway bridge of Neijiang-Kunming railway line. Some meaningful conclusions are drawn as follows. 1) Calculation formulas considering high-order mode are proposed for improving the modal Pushover analysis. 2) According to the Code of Seismic Design for Railway Engineering, 320 records of strong earthquakes are appropriately selected to statistically derive the elasto-plastic demand spectra and strength reduction factor spectra as design spectra for improving the capacity spectrum method. 3) Based on the 8# tall pier with the height of 110m, the practicability of improved capacity spectrum method considering high-order mode for seismic performance assessment of bridges is validated. Therefore, research achievements in this study can be referred by the researches in similar projects.