美国NEHRP规范中地震作用的比较研究

从1985年第一版推荐性的NEHRP规范出版以来,它已渐渐成为美国各样板规范和其他地方性建筑规范的主要参考资料之一。本文从设计加速度反应谱的最大值和长周期下降段形状等方面,对不同版本的NEHRP规范进行了比较。从中看出,在确定设计加速度反应谱时,分别考虑了场地条件在长、短周期的影响;控制长周期幅值的下降段的下降速率逐渐增大等。这些有望为我国建筑抗震设计规范的修订提供一些启示。

Comparative Study on Earthquake Action in NEHRP Building Code Provisions

The recent editions of NEHRP recommended provisions for seismic regulations for new buildings and other structures have been adopted as one of the main references of modal or local design codes in US gradually since the first edition prepared by the Building Seismic Safety Council for the Federal Emergency Management Agency was published in 1985.The differences about the maximum and the descending shape at long periods in recent editions are discussed.Some conclusions are drawn,such as the influence of local soil conditions on spectral amplitudes at long periods and short periods is considered when acceleration response spectra is determined,and the amplitudes at long periods decreased vary with the increasing of periods.All of these are expected to provide some enlightenment for the redaction of Code for seismic design of buildings in China.