多点激励下大跨度连续刚架拱组合桥的空间地震响应分析

新光大桥位于广州新光快速路主干线,是世界上第一座三跨连续钢桁拱与钢筋混凝土V型刚构结合的钢-混凝土组合体系桥梁,主桥跨度为177 m 428 m 177 m,在目前同类型桥梁中,主桥长度位居世界第一. 该桥结构新颖、造型独特. 本文以广州新光大桥为例,详细分析了大跨度连续刚架-拱组合结构桥梁在纵桥向和横桥向地震一致激励和多点激励作用下的地震响应. 研究表明多点激励对主拱肋上、下弦杆以及V型刚架斜腿地震内力响应均有较大影响,而对边拱肋轴力影响很小,并且纵桥向多点激励要比横桥向多点激励对结构的影响要明显.

Spatial seismic response analysis of long-span combined bridge of continuous rigid-frame and arch structure under multiple support excitation

Xinguang Bridge locates at Xinguang express way of Guangzhou city.It is the first 3-span continuous rigid-frame and steel-truss arch bridge with reinforced concrete V-shaped rigid frame in the world.The span of the main bridge is 177 m+428 m+177 m.Among the same type of the bridges,the main bridge is longest in the world.The style of the bridge is unique and fashionable.This paper is focused on the study on the seismic characteristics of Xinguang Bridge under synchronous and multiple support seismic excitation by subjecting the bridge to earthquakes in the longitudinal and transverse direction of the bridge.The analysis results show that multiple support seismic excitations have impact effect on the internal force of upper chord and lower chord of main arch ribs,and V-shaped rigid frames,whereas have little effect on internal force of side arch ribs.It can be also found that the influence of longitudinal multiple support excitation on the internal forces is more predominant than the transverse multiple support excitation.