超高层建筑结构体系复杂,采用精细化有限元模型进行结构弹塑性分析不仅计算工作量大,而且建模困难,难以在初步设计阶段结构体系对比中加以应用。因此,本文以某500m级超高层建筑为研究对象,通过建立其简化(鱼骨)模型,把握其关键受力特性,可以有效降低弹塑性分析的计算量,且通过大量弹塑性时程分析,对比不同结构体系的抗震性能,为结构设计提供参考。
Development and application of a simplified model for the design of a super-tall mega-braced frame-core tube building
Engineering Structures, 2016, 110: 116-126.
Abstract: Resilience-based earthquake design for next-generation super-tall buildings has become an important trend in earthquake engineering. Due to the complex structural system in super-tall buildings and the extreme computational workload produced when using refined finite element (FE) models to design such buildings, it is rather difficult to efficiently perform a comparison of different design schemes of super-tall buildings and to investigate the advantages and disadvantages of different designs. Here, a simplified nonlinear model is developed and applied to compare two design schemes (i.e., the fully braced scheme and half-braced scheme) of a super-tall mega-braced frame-core tube building, which is an actual engineering project with a total height of approximately 540 m. The accuracy of the simplified model is validated through a comparison of the results of modal analyses, static analyses and dynamic time history analyses using the refined FE models. Subsequently, the plastic energy dissipation of different components and the distribution of the total plastic energy dissipation over the height of the two design schemes are compared using the proposed simplified model. The analyses indicate that the fully braced scheme is superior because of its more uniform energy distribution along the building height and the large amount of energy dissipated in the replaceable coupling beams, which enables rapid repair and re-occupancy after an earthquake. In contrast, the potential damage in the half-braced scheme is more concentrated and more severe, and the damage in the core tubes is difficult to repair after an earthquake.
Keywords: super-tall building; simplified model; resilience; plastic energy dissipation; plastic energy distribution.