多塔斜拉桥地震作用简化分析方法

The simplified method for the longitudinal seismic response analysis of the multi-tower cable stayed bridge

多塔斜拉桥多为对称结构,受实验室规模及振动台台组数的限制,大型多塔斜拉桥的大比例尺全桥多振动台试验无法进行,需要提出合理有效的简化分析方法:采用类似于静力学中的方法取反对称半结构,然后进行纵桥向一致地震激励。本文以南昌朝阳大桥(六塔斜拉桥)为工程实例验证动力荷载作用下非线性体系半结构简化的合理性,通过对比全、半桥结构计算得到的支座位移、墩底内力和主梁位移,发现半结构与全结构具有相同的计算精度。该简化方法为实现多塔斜拉桥大比例尺简化振动台试验提供了理论依据。

Multi-tower cable-stayed bridges are usually symmetrical structures. However, shaking table test forlarge scaled models can not be carried out due to the limitation of shaking tables. Therefore, a simplified methodfor seismic analysis needs to be proposed. A simplified method in statics is introduced to deal with this problem. Inthis paper, the Chaoyang Bridge （a six-tower cable-stayed bridge） was taken as an engineering case to verify thereasonability of a presented simplified method. By comparing the bearing displacement, girder displacement andpier force between the half bridge model and whole bridge model, the consistency of the results of the two systemshad been revealed. This simplified method proposed in this research offers theoretic support for large scale shakingtable test.