贵广铁路东平水道特大桥抗震设计研究

东平水道特大桥主桥双线铁路(85.75+286+85.75)m钢桁架拱桥,为国内首座该类型铁路桥梁。桥位处抗震设防烈度为7度,主桥的地震设防为设计关键。建立主桥三维有限元抗震模型,详细研究在33号活动墩墩顶不设置或设置液体黏滞阻尼器装置对主桥的抗震影响效果,采用反应谱和时程两种分析方法,对抗震分析结果进行比较。结果表明:(1)地震反应不控制钢桁架拱桥和桥墩身结构设计,仅控制桩基础设计;(2)33号活动墩墩梁间设置纵向减隔震液体黏滞阻尼器,对32号固定墩纵向抗震响应影响不大,效果不明显;(3)给出的最小配筋率均能满足各桥墩桩基础抗震验算及预期的抗震要求。

Study on Anti-seismic Design of Dongping Waterway Grand Bridge on Guiyang-Guangzhou Railway

The main bridge of Dongping Waterway Grand Bridge is the first steel trussed arch railway bridge in China. It carries double track railway and the span is( 85. 75 + 286 + 85. 75) m. Anti-seismic design of this structure is important because of the high seismic fortification intensity in the site of the bridge( 7 degree). In this paper,a 3D finite element model is established to study the influences of the fluid viscous damper on structural seismic response. This fluid viscous damper is installed on top of pier33# with hinge bearing. Results of spectrum analysis and time history analysis are compared. The results indicate that:( 1) the design of pile foundation is controlled by seismic actions but the design of steel trussed arch and pier is not;( 2) the fluid viscous damper installed on pier 33# has little effect on 32#rigid pier;( 3) the minimum reinforcement ratio of pile foundations given in this paper meets the requirements of seismic checking and estimated seismic performance.