考虑行波效应的某大跨桥梁地震响应分析

Seismic Response Analysis of A Large-span Bridge Considering Traveling Wave Effect

在一致激励和非一致激励作用下分别计算了某大跨度桥梁结构的地震响应,对比分析了桥梁结构的位移反应、杆件内力和桥墩处剪力,分析了行波效应对大跨度结构反应的影响程度。同时分析了在不同行波速度下行波效应的影响程度。结果表明,当考虑地震行波效应时,桥梁结构部分节点位移反应增大;桥墩处斜撑杆件轴力增大,部分杆件内力基本不变;全部桥墩的总地震剪力减小,但各桥墩处剪力均有所增大。当考虑不同波速影响时,随着地震波速增加,节点的相对位移减小,各桥墩基底剪力和部分杆件内力减小,但均比一致激励时大。

The nodal displacement response,member force and pier shear force of a large-span bridge were analyzed by computing its seismic responses under the uniform earthquake excitation and inconsistent excitation respectively to further study the effect of the traveling wave on large-span structural responses.Meanwhile,the effect of the wave traveling velocity on the structural responses was analyzed.The results show that when the traveling wave is applied on the structure,some nodal displacement responses and some member axial forces especially in diagonal braces on piers increase while other member internal force varies slightly.Although the total seismic shear force of the four piers is reduced,the shear force of each pier increases.When the traveling wave velocity increases,the nodal relative displacement responses as well as the base shear and the member internal force on the piers reduce,but the responses are larger than those under the uniform excitation.