索穹顶结构地震作用计算方法的对比分析  

Comparative analysis on earthquake action calculation methods of cable dome structures

作　　者：谯钰 刘宏创[1,2] 邓华 董石麟[1] QIAO Yu;LIU Hongchuang;DENG Hua;DONG Shilin(Space Structures Research Center,Zhejiang University,Hangzhou 310058,China;Center for Balance Architecture,Zhejiang University,Hangzhou 310028,China)

机构地区：[1]浙江大学空间结构研究中心,浙江杭州310058 [2]浙江大学平衡建筑研究中心,浙江杭州310028

出　　处：《建筑结构学报》2023年第12期59-71,共13页Journal of Building Structures

基　　金：国家自然科学基金项目(51978605)。

摘　　要：由于结构的几何非线性,我国GB 50011—2010《建筑抗震设计规范》中并未对以索穹顶为代表的柔性大跨屋盖结构的地震作用计算方法作出明确规定。为此,以重力荷载代表值作用下的平衡构型为考察对象,通过与时程分析法计算结果进行对比,考察振型分解反应谱法用于索穹顶结构地震作用计算的适用性。为保证地震动输入的一致性,时程分析时使用由设计反应谱生成的人工地震波。基于振型参与质量系数,提出了一种判别屋盖索穹顶结构地震作用主要贡献振型的指标,并指出应采用对屋盖索穹顶结构的地震作用提供主要贡献的振型确定瑞利阻尼系数,否则时程分析时将显著高估结构阻尼效应并造成结构地震响应的计算结果偏小。采用两种方法计算索穹顶结构在不同挠跨比限值(预应力水平)下的多遇地震响应。结果表明,对于满足非抗震设计验算的Geiger型和Levy型索穹顶算例,振型分解反应谱法计算得到的结构地震响应与时程分析法的结果匹配良好,验证了该方法进行此类柔性屋盖结构地震作用计算的适用性。Due to the structural nonlinearity,the earthquake action calculation method for the flexible long-span roof structures,typical cable domes,has not been specified in the GB 50011—2010‘Code for seismic design of buildings’.For the equilibrium configuration under the representative value of gravity load,the applicability of the mode-superposition response spectrum method to calculate the earthquake action of cable dome structures is investigated by comparing the calculation results with those obtained by the time history method.Artificial seismic waves are generated according to the design response spectrum and employed in the time history analysis to ensure the consistency of seismic inputs.It is pointed out that the Rayleigh damping coefficients should be determined based on the mode shapes dominantly contributing to the earthquake action of the roof cable dome structure,otherwise a significant overestimation of the structural damping effect will occur in the time history analysis and result in an underestimation of the obtained structural seismic responses.Based on the modal participating mass factor,an index is proposed for judging the mode shapes which are dominantly contributing to the earthquake action of the roof cable dome structure.The two methods are employed to calculate structural responses of cable dome structures under the frequent-occurred earthquake corresponding to different deflection-span ratio limits(prestress levels).For the illustrative Geiger and Levy cable domes that both satisfy the non-seismic design check,the calculation results show that the structural seismic responses obtained by the mode-superposition response spectrum method well match with those obtained by the time history method,and its applicability for the seismic action calculations of this type of flexible roof structure is verified.

关 键 词：索穹顶 地震作用计算 振型分解反应谱法 时程分析法 瑞利阻尼模型 振型参与质量系数 

分 类 号：TU394[建筑科学—结构工程] TU311.41