振型分解反应谱法计算加层后结构的几个问题研究  

Some research and discussion about the modal response spectrum method for story added existing structures

作　　者：肖川 史跃波 张欣 Xiao Chuan;Shi Yue-bo;Zhang Xin(China Academy of Building Research,Beijing Glory Technology Co.Ltd,Beijing 100013,China)

机构地区：[1]中国建筑科学研究院有限公司北京构力科技有限公司,北京100013

出　　处：《工程抗震与加固改造》2024年第4期164-171,共8页Earthquake Resistant Engineering and Retrofitting

基　　金：“十四五”国家重点研发计划项目“支持非线性几何特征建模的建筑信息模型(BIM)平台软件”(2022YFC3802100);“十四五”国家重点研发计划课题“非线性几何特征建模关键技术研究和BIM协同设计平台研发”(2022YFC3802102)。

摘　　要：在既有钢筋混凝土结构或砖混结构上加建钢结构层后,应采用整体模型进行抗震计算。由于加层部分与既有结构的阻尼特性不同,不能采用统一的振型阻尼比,本文研究了估计混合结构振型阻尼比的实用计算方法。为确保反映出加层结构部分的高阶振型响应,本文引入了部分结构的有效质量系数的计算方法。最后,探讨了加层结构与既有结构的动力相互作用问题,分析了加层后结构层剪力相对于原结构降低的原因。本文研究的计算方法均已在PKPM程序中实现,选用这些方法可以更准确地进行既有结构的加层改造计算。The new structure after adding stories is often composed of existing reinforced concrete structure or brick structure and steel structure.Aseismic calculation of such structures should be based on undivided model.The damping characteristics are different between the several parts,so it is less accurate to use a uniform modal damping ratio.A practical method for calculating the modal damping ratio is studied.In order to consider the high-order modal response of the new added structure,the calculation method of the effective mass coefficient of part structure is introduced.Finally,the dynamic interaction between the added structure and the existing structure is discussed,and the reason for the decrease of the base shear force is proposed.The above methods have been added to the PKPM,which is a software system for structure design,to improving the accuracy of aseismic calculation.

关 键 词：既有结构 加层 阻尼比 有效质量系数 

分 类 号：TU311.4[建筑科学—结构工程]