大跨度钢箱提篮拱桥地震反应的分析方法

Methods of seismic response analysis of long span X-style steel box-section arch bridge

基于有限元理论,应用大质量法(LMM)和拱脚固定法建立大跨度钢箱提篮连拱桥的空间动力计算模型.在考虑箱型拱肋翘曲和剪切变形的基础上,对连拱桥进行非线性地震时程反应分析,验证大质量法的科学性.复核了结构体系满足当地抗震设防要求,发现钢箱拱肋某些部位的扭力和剪力明显,建议设计时予以考虑.

Based on finite element theory, the 3 dimensional dynamic evaluation model of long-span X- style steel box-section arch bridge was created with large-mass method （LMM） and fixed arch foot method. Then its nonlinear time history seismic response was analyzed with a consideration of warping and shear deflections of box arches, so that the scientific reasonableness of LMM was verified. The checking computation proved that the structural system of the bridge was appropriate for the anti-seismic require- ments. It was found, however, that the torsion and shear forces acting on some parts of the arch ribs were larger significantly, so that it should be suggested that both of them would be considered in design.