（1 广州市设计院，510620；2 西安建筑科技大学土木工程学院，710055）

［提要］在建立60，80，100，125，150m跨度张弦桁架模型的基础上，进行了自振特性分析。采用振型分解反应谱法和时程分析方法对竖向地震作用进行了分析，得到了小震、大震作用下动内力分布规律。计算分析了高跨比、预应力、斜放等因素的影响。对结果的统计分析表明，各模型具有相同的动内力分布特点，总结了张弦桁架动内力计算简图及参数，结果可供张弦桁架设计参考。

［关键词］张弦桁架；竖向地震反应；动内力

Dynamic Characteristic Study of Large-span Truss String Structure Under Vertical Seismic Action/Xiong Wei¹,Han Jianqiang¹,Wu Minzhe²(1 Guangzhou Design Institute,Guangzhou 510620,China; 2 College of Civil Engineering, Xi′an Univ. of Arch. & Tech., Xi′an 710055,China)

Abstract:Truss string structure models of 60m, 80m, 100m, 125m, 150m span are developed, and  their vibration characteristic by frequency domain analysis is got. The distribution of dynamic internal force is analyzed by time history method and response spectrum method, as well as, height span ratio, prestress, sloping support are also discussed. Analysis indicates that all truss string structure models have the same distribution law of dynamic internal force by statistics method.The figure about dynamic internal force distribution and factor are presented.

Keywords:truss string structure； vertical seismic response； dynamic internal force