针对城市高架小半径曲线梁桥弯扭耦合严重、地震危害明显的特点,对武汉新站小半径曲线梁桥有效的动力计算模型进行了探讨,比较了单根梁模型、板壳模型和脊梁模型在模拟小半径曲线桥时的准确性和精度.在脊梁模型的基础上,基于时程分析方法,采用三向地震波同时输入方式,分析了小半径曲线桥的动力特性及其地震响应的主要影响因素.分析结果表明:脊梁模型是对小半径曲线桥进行动力分析的有效实用方法;后续结构、桩-土-桥的相互作用、桥墩刚度及支座偏心等敏感因素对小半径曲线桥的地震响应有较大的影响,计算分析时应给予足够重视.%Aiming at severe bending-torsion coupling and noticeable earthquake damage of a small-radius curved bridge in urban viaducts, the reasonable and effective dynamic FE models of the bridge were discussed. The accuracy and validity of three models including shell element model, single beam one and spine-like beam one were compared. On the basis of spine-like beam model, the time-history analysis method and multiple earthquake excitations were adopted, with those the dynamic properties and the dominant seismic influencing factors of the small-radius curved bridge were analyzed. The analysis results indicated that the spine-like beam model can be regarded as an effective and practical method when performing dynamic analysis of small-radius curved bridge; besides, the adjacent structure, pile-soil-bridge structure interaction, pier rigidity and support eccentricity have greater influences on the bridge, these factors should be paid enough attention to during design and analysis.
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