【摘要】 基于多自由度空间体系地震响应分析的基本理论,得到大跨度桥梁的空间地震响应分析方法,并运用线弹性有限元理论将其程序化,分析过程包括桥梁有限元建模、地震动的选择、动力时程分析等。以重庆朝天门长江大桥—三跨中承式连续钢桁架拱桥为例,分别研究大跨度钢桁架拱桥在一致激励和行波效应作用下的地震响应。研究结果表明:对于此类型桥梁的拱肋,在一致激励下,纵向位移最大峰值出现在1/4中跨附近,中跨下拱肋左拱脚处的单元内力峰值最大;竖向地震动和行波效应对结构位移和内力的影响较大。更多还原

【Abstract】 Based on the analysis theory of seismic response for multi-freedom space system,a seismic response analysis procedure of long-span bridges was obtained and programmed with linear elastic finite element method.The procedures included finite element modeling,selection of ground motions and dynamic time-history analysis of the bridge and so on.A 3-span semi-supported continuous steel truss arch bridge,namely the Chongqing Chaotianmen Yangtze River Bridge,was taken as an example,the seismic characteristics of the bridge was investigated during uniform excitation and traveling wave excitation,respectively.The analysis results show that the maximal peak value of longitudinal displacement appears around the 1/4 of the center span for the arch rib of this bridge during uniform excitation,and the peak value of element internal force,which is around the left foot arch of the underlying arch rib,is maximal.The vertical earthquake ground motion and the traveling wave effects may affect the displacements and internal forces of the bridge greatly.更多还原