多维地震激励作用下大跨度斜拉拱桥的随机响应

以一种新颖钢管混凝土拱桥-斜拉钢管混凝土拱组合桥为研究对象，通过建立空间结构有限元模型，利用子空间迭代法得到结构的自振特性，并运用随机响应理论分别对该桥在纵向激励、纵＋竖向激励、纵＋横向激励、纵＋竖＋横向激励等4种工况作用下的地震响应与相同跨径的中承式钢管混凝土拱桥进行了对比分析。分析结果表明，地震横向激励对斜拉拱桥的响应特性有较大的影响，在多维随机地震激励作用下，由于斜拉索的存在使得斜拉拱桥的横向抗震性能优于相同跨径的中承式钢管混凝土拱桥，这为大跨度斜拉拱桥的抗震设计和研究提供了理论依据。

Stochastic Response of Cable-stayed Arch Bridge under Multi-component Seismic Excitation

A 3D finite element model for a long span cable-stayed concreted-filled steel tubular arch bridge was established.Based on the model and the dynamical equation of MDOF structural system,natural vibration characteristics was obtained by use of subspace iterative method.In addition,3D seismic response of this bridge was studied by means of the random vibration theory subjected to longitudinal excitation,longitudinal and vertical excitation,longitudinal and transverse excitation and 3D excitation.Compared to the seismic response of this bridge with the same span arch bridge induced by the earthquake excitation,the results show that,the effect of transverse excitation lateral stability on the subject bridge is notable;the whole aseismatic capabilities of the subject bridge is better than that of long span concrete-filled steel tube(CFST) arch bridge under multi-component seismic excitation oweing to the existing of stay cables.It provides a theoretic basis for seismic design and study of cable-stayed arch bridge.