钢结构混合式交错桁架体系的横向合理结构布置探讨

通过弹性反应谱法和弹性时程分析法对13个钢结构混合式交错桁架体系算例进行了参数分析,对中、高层交错桁架体系的建筑物高宽比、桁架高跨比、横向支撑形式和阻尼比等对结构抗震性能的影响进行了探讨.研究结果表明:(1)混合式交错桁架体系薄弱层位于底层;(2)结构最大层间侧移角随高宽比的增大而增大,但均能满足抗震规范的要求;(3)合理的桁架高跨比在1/5左右;(4)改变底部斜撑为风撑、加强横向支撑等措施可以有效地减小结构最大层间侧移角;(5)体系的阻尼比对其层间侧移角有较大影响,提高阻尼比到0.05,结构的层间侧移角有较大幅度的降低等.研究结果可供规程制订和工程设计参考.

Study on the rational structural transverse layout of steel staggered truss system with composite truss

To evaluate the seismic behavior of steel staggered truss system with composite truss,parameter analysis was carried out with 13 examples by performing elastic response spectrum analysis and elastic time-history analysis.Parameters analyzed here include the effect of height-to-width ratio of the building,the aspect ratio of the truss,the transverse brace arrangement and the damp ratio.General conclusions and suggestions were arrived at by the analysis,which may be used to draw up specification and to guide the practice design.The conclusions and suggestions obtained were as follows:(1) The weakest story of the system lied in the first story;(2) The story drift angle increases with the height-to-width ratio;(3) The rational aspect ratio of the truss is about 1/5;(4) The reinforcement of transverse brace may decrease maximum story drift angle effectively;(5) The damp ratio has large effect on the story drift angle.