中美高层钢筋混凝土框架-核心筒结构抗震设计对比

COMPARISON OF SEISMIC DESIGN OF HIGH-RISE RC FRAME-CORE TUBE STRUCTURE BETWEEN CHINA AND AMERICA

为综合对比中美抗震设计规范体系的总体效果,根据美国太平洋地震工程研究中心(PEER)给出的典型高层钢筋混凝土框架-核心筒结构案例的设计结果,采用中国规范对其进行了对比设计研究,详细分析了按照中、美规范设计得到的结构构件尺寸、动力特性、设计地震作用和材料用量。并建立了中美两个结构的弹塑性有限元模型,初步研究了二者的抗震性能。通过研究发现,中美抗震设计方法存在较大差异。该研究中,在相同地震危险性情况下,我国规范反应谱的设计地震作用较大,并且我国规范对结构层间位移角的限制比较严格,二者使得按照中国规范设计的结构其设计地震作用以及材料用量均显著高于美方设计结果。但中美设计方案在不同强度地震作用下的抗震性能基本相当。该文对比结果可供我国高层建筑抗震设计研究参考。

To illustrate the main differences in structural seismic design codes between China and the United States from a structural system viewpoint, a comparative evaluation was conducted on a typical tall reinforced concrete(RC) frame-core tube building, a widely used structural form in both countries. The building, for which the original design information was provided by the Pacific Earthquake Engineering Research Center(PEER), was first redesigned according to Chinese seismic design codes. Next, the component dimensions, dynamic characteristics, seismic design forces and construction material consumptions in these two buildings were compared in detail. Subsequently, nonlinear finite element models of the two buildings were constructed to evaluate their seismic performances under different hazard level earthquakes. This study finds that there are clear differences between Chinese and U.S. seismic design methods. For this tall building, the seismic design forces determined by Chinese response spectrum are larger than that determined by U.S. spectrum at the same seismic hazard level, and the Chinese codes specify a stricter inter-story drift ratio requirement, leading to larger seismic design forces and a correspondingly higher amount of material consumption. However, the two buildings exhibit roughly similar performances under earthquakes. These observations provide useful information for further optimization of the design of tall buildings in China.