超高层钢筋混凝土框架-核心筒结构的抗震特性分析

运用大型有限元软件ANSYS对某超高层钢筋混凝土框架-核心筒结构进行模态分析,并通过设计软件ETABS的计算结果对其进行验证,得到结构的自振特性。在模态分析的基础上,采用时程分析法对该结构进行非线性地震分析,对结构输入3种不同的地震波进行计算,充分分析和比较了计算结果,包括层间位移角沿高度变化包络曲线、顶点水平位移时程曲线、层间位移沿高度变化包络曲线以及顶层加速度时程曲线。结果表明:在地震作用下,该结构没有出现较为明显的薄弱层,同时结构的最大层间位移角出现在结构的中上部,且其值小于《高层建筑混凝土结构技术规程》规定的1/100,能够满足抗震设防要求。利用ANSYS和ETABS对结构进行非线性地震分析,反映了此类结构体系在地震作用下的动力特性,解决了设计中的疑难问题,并校验了结构设计方案的合理性。研究结果在超高层结构抗震设计方面具有重大的理论意义和实用价值。

SEISMIC CHARACTERIZATION ANALYSIS OF THE SUPER HIGH-RISE BUILDING WITH THE REINFORCED FRAME-CORE TUBE STRUCTURE

According to an actual super high-rise building with the frame-core tube structure,mode analysis of a super high-rise reinforced concrete frame-core tube structure is discussed by using large-scale finite element software ANSYS,whose calculation results are verified through the design software ETABS,from which the characteristics of nature vibration is obtained. Based on the modal analysis,nonlinear seismic analysis of structure is carried out by the time-history analysis method. Inputting three different seismic waves to structure whose calculated results are fully analyzed and compared,including floor displacement angle envelope curves,vertex displacement time-history curves,floor displacement curves and time-history curve of roof acceleration. The results show that the maximum damage of concrete exists in the bottom of super high-rise building with the frame-core tube structure,the structure has no obvious weak story and maximal floor displacement angle occurs in the upper floors,and its value is less than 1 /100 of Technical Specification for Concrete Structures of Tall Building and can meet the code requirements for energy dissipation structures. A 3-D finite element analysis is conducted to evaluate nonlinear seismic analysis of the structure by using ANSYS and ETABS,which reflects the dynamic characteristics of this kind of structure under seismic action and solves design difficult problems and verifies the feasibility of the design scheme. The results have important theoretical and practical value in the seismic design of super high-rise buildings.