主梁不同模型对结构地震响应影响的比较

Comparison of Influence of Different Models for Girders on Structural Seismic Responses

以一典型城市高架梁桥为例,对上部结构采用不同主梁模型对结构地震响应的影响进行了分析研究,分别采用脊骨梁模型和板壳单元模型对主梁结构进行模拟,并基于有限元软件sap2000对两种不同主梁模型下结构的地震响应进行了分析,得到两种模型下的结构动力特性及下部结构桥墩的地震响应值。分析结果表明,对于存在长悬臂盖梁的梁桥,盖梁的响应以及横桥向下部桥墩的延性响应均对主梁的模型比较敏感。建议对于这类梁桥,上部结构的模拟应采用比较精细的有限元模型来合理考虑上部结构的刚度、质量的分布。

The influence of different models for girders of superstructure on structural seismic responses was analyzed in this paper taking a typical viaduct as an example. The spine beam model and the shell element model were used to simalate the girder structure. The seismic responses of the structure were analysed with the two different models by using software sap2000. The result indicates that for bridges with long cantilever cap beam, the seismic responses of cap beam and the column transverse ductile flexural responses are sensitive to the finite element model of the girder. It is suggested that for this type bridge, the distributing of the stiffness and the mass of the girder should be modeled rationally.