大跨梁桥施工全过程地震响应非线性影响分析

Nonlinear Influencing Analyses of Long Span Girder Bridge's Seismic Response for Whole Construction Process

考虑各种非线性因素影响,对三座典型大跨连续梁桥,花瓶型实体桥墩桥梁、矩形空心薄壁桥墩桥梁和双柱实体桥墩桥梁进行施工全过程非线性时程分析,评价非线性因素对大跨梁桥施工全过程地震响应的影响程度。研究结果表明,非线性时程分析的地震响应峰值主要集中于8#梁段、9#梁段、边跨合拢、体系转换、中跨合拢和桥面施工等阶段,在抗震设计过程中应予重点关注。总体上矩形空心薄壁桥墩桥梁在整个施工过程中表现出较大的抗震刚度,双柱实体桥墩桥梁次之,花瓶型实体桥墩桥梁最小。各种非线性因素对桥梁的地震响应随施工阶段推进而变化的规律影响不大,对大跨梁桥施工全过程地震响应的数值大小影响明显。

Considering kinds of nonlinear factors, the nonlinear time history analyses for whole cantilever construction were studied and compared with each other for three long span typical continuous girder bridges, the vase-type solid pier bridge, the thin-wall type rectangular hollow pier bridge and the double-column type solid pier bridge. And the influencing degree of the nonlinear factors was evaluated for the seismic responses of the whole construction process. The results show that the seismic response peaks mainly focus on the 8#, 9# girder segment, the side span closure, the system transformation, the middle span closure and the deck construction stages, which should be paid more attention in seismic design. The bridge with the thin- wall type rectangular hollow piers has the maximum seismic stiffness in a great degree, the bridge with the double-column type solid piers takes second place and the bridge with the vase-type solid piers has the minimum stiffness. The nonlinear factors have little influence on the variation law of the seismic responses along with the construction stages. However the nu- merical values of the seismic responses are influenced obviously by the nonlinear factors for the whole construction process.