三跨斜交T梁动力特性分析

以107国道深圳元朗斜交桥为背景,首先对全桥进行环境振动测试,利用频域中的峰值法（PP）和时域中的随机子空间识别法（SSI）识别出三跨斜交T梁桥的频率、振型和阻尼比;利用ANSYS软件建立了全桥三维有限元模型,进行理论模态分析并和实测结果进行比较,并进一步分析了不同斜交角时动力特性的差异,探讨了此类斜交桥的动力特性。

DYNAMIC ANALYSIS OF A SKEWED T-GIRDER BRIDGE WITH THREE-SPANS

The ambient vibration field testing of a skewed T-girder bridge,called "Yuanland bridge" on the G107 line of national highway is firstly carried out.The peak picking(PP) method in frequency domain and the stochastic subspace identification(SSI) method in time domain are applied to identify the modal parameters of the bridge,such as frequencies,modal shape,and damping ratios.Based on its 3-D finite element(FE) model constructed using ANSYS program,its theoretical modal analysis is performed.The results from FE modl are compared with those from field testing.The dynamic behavior of this kind of bridge with different skewed angles and same spans are compared to reveal the dynamic characteristics of the skewed T-girder bridge.