高层建筑的隔震原理与技术

Theory and Techniques of Seismic Isolation in High-rise Buildings

隔震技术目前正逐渐应用于高层建筑。但对于高层建筑,延长结构周期带来的抗震性能改善并不显著,而分析结果表明,隔震技术仍可以显著降低结构的绝对加速度响应。本文以线弹性动力时程分析和反应谱法为基础,从延长结构周期原理与隔震层滤波原理两方面分析了建筑隔震的减震效果。分析结果表明,在现有基于承载力抗震设计框架下,两种原理的分析结果是等效的,而滤波原理能够更加科学的解释隔震技术在降低结构绝对加速度响应方面的减震机理,有助于从基于性能设计更加全面的体现隔震技术的优势。在充分认识隔震原理的基础上,进一步讨论了高层建筑隔震需解决的技术问题,并介绍了日本高层隔震建筑的应用。

Seismic isolation has been applied to more and more high-rise buildings in the recent years. Its benefit of mitigating the seismic response by increasing the structure＇s period is, however, not as significant as in low-rise buildings. On the other hand, the analysis results show that the seismic isolation is quite effective in reducing the absolute acceleration response even for high-rise buildings. Based on both linear-elastic dynamic and response spectrum analyses, two interpretations of base isolation building structures, the period elongation and the ground motion filtration, are discussed and compared. These two interpretations are proved equivalent for current force-based seismic design procedures, while the latter is much more reasonable in explaining the reduction effect of absolute acceleration and hence better illustrates the advantages of seismic isolation in accordance with philosophy of the performance-based earthquake engineering. Some technical problems for high-rise base isolation building are also discussed. And some applications of high-rise base isolation buildings in Japan are also introduced.