大跨径连续刚构桥的动力性能及地震响应分析

Analysis on Dynamic Characteristics and Seismic Responses for Long-span Continuous Rigid-framed Bridges

以苏通长江大桥辅航道桥为工程背景,建立了该桥的动力分析模型,考虑了结构自重的几何非线性影响和桩土的影响,在此基础上研究了该桥的动力特性和多支承激励地震响应,并探讨了行波效应对大跨度刚构桥地震反应的影响。结果表明,模型及其边界条件的正确模拟对分析结果的影响很大,行波效应产生的不利影响十分突出。

Taking the under construction approach bridge of Sutong Bridge over Yangtze river as the en gineering background, a dynamic model for it is established with consideration of geometrical nonlinearity, which is caused by dead weight and the interaction between soil foundation and structure. Based on it, dynam ic characteristic is studied and multi support excitations seismic response is derived using Large Mass Method. The wave passage effect on the seismic response is studied in detail. The numerical result indicates that ration al modeling of the boundary condition can affect greatly to the analysis result, the wave passage effect should be seriously considered in the seismic design of Long Span Continuous Rigid Framed Bridges. The modeling method and the dynamic results in this paper can provide reference for the engineering design and structural composition improvement of bridges of this kind.