大跨桥梁非一致激励地震响应分析

目前一致激励被广泛应用于工程结构的地震响应分析中,但对于跨度和支点距离较大的大跨桥梁,非一致激励效应的影响越发明显,有必要针对悬索桥和斜拉桥等大跨桥梁进行非一致地震激励响应研究.以一座大跨度斜拉桥为例,考虑行波效应、部分相干效应和局部场地效应,对非一致激励对大跨桥梁地震响应的影响进行了分析.研究结果表明一致激励并不能控制大跨桥梁的地震设计,非一致激励的影响明显,应在同类桥梁的抗震分析中予以计入.

Seismic response analysis of long-span bridge under non-uniform excitation

Currently, the method under uniform seismic excitation is widely applied in earthquake response analysis of practical projects. However, for the long-span bridge, large distance of supports and long extension makes non-uniform seismic excitations effect become very distinct. Consequently,seismic response research under non-uniform excitation of random earthquake ground motion is necessa-ry for anti-seismic design of long-span bridge. Seismic response analysis of a long-span cable-stayed bridge is simulated under random seismic excitations in stochastic method in this study. Traveling wave effect, "partial coherence effect and local site effect are considered in the study. The result indicates that uniform seismic excitation does not control the seismic design of long-span bridge and the influence of traveling wave excitation and multi-support excitation of random earthquake ground motion on the seismic responses must be considered.