环境激励下刚架拱桥模态识别与可靠度评估

Modal Identification and Reliability Assessment of Rigid-Frame Arch Bridge under Ambient Excitation

摘要:

某城市道路项目在更新改造过程中，某刚架拱桥出现显著结构损伤。以该桥为对象，采用随机子空间法开展模态识别，结合空间有限元法分析其动力性能，并基于响应面法评估结构可靠度。结果表明，桥梁实测频率略低于有限元理论值，验证了模态参数识别的有效性，并实现了对结构可靠性的定量评价。研究成果可为同类在役桥梁的有限元模型修正、可靠性评定及维修加固提供理论支撑。

Abstract:

During the reconstruction and upgrading of an urban road project, the significant structural damage is identified in a rigid-frame arch bridge. Taking the bridge as the object, the stochastic subspace method is used to carry out the modal identification. Its dynamic performance is analyzed in conjunction with the spatial finite element method, and based on the response surface method, the structural reliability is assessed. The results indicate that the measured bridge frequencies are slightly lower than the theoretical finite element values, validating the effectiveness of modal parameter identification and achieving a quantitative assessment of structural reliability. The research outcomes can provide theoretical support for finite element model modification, reliability evaluation and maintenance reinforcement of similar in-service bridges.