大跨度钢管混凝土拱桥地震响应分析

采用大型通用有限元前后处理软件MSC Patran建立大跨度铁路钢管混凝土拱桥的有限元模型.根据地震响应分析输入地震波的选择原则及桥址地震烈度,选用经过加速度幅值调整的EL-Centro地震波作为输入地震波,进行大跨度铁路钢管混凝土拱桥在水平地震波、三向地震波、一致激励和多点激励下结构的地震响应分析.分析结果表明:结构在水平地震波和三向地震波作用以及在一致激励和多点激励作用的地震响应差别很大,且没有简单明确的变化规律,因此必须采用同时考虑三向地震波和多点激励共同作用的动态时程分析法才能较真实的反应结构在地震作用下的实际受力状态和变形性能.

Seismic Response Analysis of Long-Span CFST Arch Bridges

The finite element model of a long-span Concrete-Filled Steel Tubular(CFST) arch bridge was founded by using the large-scale universal finite element pre/post processing software MSC Patran.Then the seismic responses of the bridge were calculated under different conditions of the horizontal seismic wave input,the three-dimensional seismic wave input,uniform excitation and multi-support excitation.Here the input seismic wave used EL-Centro wave whose amplitudes were adjusted according to the requirements of the seismic dynamic time history analysis and the seismic intensity on bridge site.The calculation results indicated that the seismic responses of the bridge varied greatly between the horizontal and three-dimensional seismic wave input,uniform excitation and multi-support excitation,with no simple and explicit variation law.So the seismic dynamic time history analysis of long-span CFST arch bridges should use three-dimensional seismic wave and multi-support excitation simultaneously in order to reflect the actual mechanical behaviour and deformation characteristics.