【摘要】 针对常规地震易损性分析方法的不足，引入基于对数变换核密度估计与Copula函数相结合的半参数(transformed kernel density estimation and Copula, TKC)构件易损性分析方法及可有效考虑构件响应相关性的基于R-vine Copula函数的系统易损性分析方法，系统开展“构件-系统”两层次易损性分析。通过与一阶界限法对比，验证了所采用方法的合理性和准确性。为揭示典型铁路减隔震桥梁系统的损伤特性及抗震性能，以某7×32 m双线铁路减隔震简支梁桥为工程背景，建立轨道-桥梁系统精细化非线性动力分析模型，实现构件及系统层面的易损性分析。构建了适用于铁路减隔震桥梁的三水准抗震性能评估体系，对桥梁抗震性能进行全面评估。研究表明：减隔震支座在地震作用下最易发生损伤，其次为轨道、桥墩；支座体系主导系统的轻微、中等损伤，轨道体系主导系统的严重损伤和完全破坏。因此，实际工程中应重点加强支座体系的抗震设计，同时采取必要措施提高轨道体系的抗震能力，确保桥梁系统整体性能达到预期标准。更多还原

【Abstract】 To address the limitations of conventional seismic fragility analysis methods, a semi-parametric transformed kernel density estimation and Copula(TKC) method based on log-transformed kernel density estimation and Copula functions was introduced for component-level analysis, which balances computational accuracy and efficiency, along with an R-vine Copula-based system-level approach that effectively accounts for the correlation among component responses. A two-level “component-system” fragility analysis was conducted. The rationality and accuracy of the proposed methods were validated through comparison with the first-order boundary method. To investigate the damage characteristics and seismic performance of a typical railway seismic isolated bridge system, taking a 7×32 m seismically isolated simply supported beam bridge with double-track railway as the case study, a refined nonlinear dynamic analysis model of the track-bridge system was established, enabling fragility analyses at both component and system levels. A three-level seismic performance evaluation framework tailored for railway seismic isolation bridges was developed to comprehensively assess bridge seismic performance. Results indicate that seismic-isolation bearings are the most vulnerable components under seismic action, followed by tracks and piers. The bearing system predominantly controls slight and moderate damage states, while the track system governs severe damage and complete failure. Accordingly, practical engineering should prioritize enhancing seismic design of the bearing system and implement necessary measures to improve track system seismic capacity, ensuring overall bridge system performance meets intended standards.更多还原