复杂形体超高层钢框架-混凝土核心筒混合结构减震的研究

Seismic response mitigation of a complex shaped composite tube structure with steel frame and concrete core

以拟建超高宁夏电视塔(NXTVT)工程为背景,利用SAP2000建立其三维有限元分析模型。超高宁夏电视塔呈现底部小、上部大、中部略呈细腰形的花瓶状复杂形体;而且,楼层的不连续分布导致结构质量和侧向刚度沿竖向分布的不均匀。因此,整体结构形式复杂,对抗震要求高。首先,对结构的动力特性进行分析研究。在此基础上,使用振型分解反应谱法和FNA动力时程法对该结构的地震反应进行多维分析。接着,对安装非线性液体粘滞阻尼器(NFVDs)结构进行动力时程分析,以评价NFVDs对该结构的多维减震性能。通过大量的计算分析与比较,综合出了许多有益的结论与建议,为该实际工程或类似工程的减震设计提供参考依据。

Taking the Ningxia TV Tower（NXTVT） as an example case of composite tube structure,the three-dimensional（3D） finite element model of NXTVT was established by resorting to SAP2000 software.The shape of NXTVT resembles a vase of small bottom,large top,and slender-middle-waist.Likewise,its floors are arranged discontinuously,thus leading to the uneven distribution of structural mass and stiffness.Hence,there is a need of high demand of seismic performance in the design of the structure.The dynamic characteristics of the structure were analyzed and investigated.Based on this,the multi-dimensional seismic responses of the structure under the operating base earthquake（OBE） with a return period of 50 years were analyzed by use of both the response spectrum method and fast nonlinear analysis（FNA） time history method.Then,the time history analysis of NXTVT with nonlinear fluid viscous dampers（NFVDs） was carried out to evaluate the seismic response mitigation performance of NFVDs for the structure under multi-dimensional earthquakes.Through extensive numerical analysis and comparisons,the conclusions obtained herein will be much useful for the design of NVFDs for NXTVT or similar projects under earthquakes.