频率非平稳对大岗山拱坝非线性响应的影响

本文以大岗山拱坝为例,研究频率非平稳特性对坝体非线性响应的影响。选择不同的实际地震动时程作为计算输入,通过研究这些时程的时频特性,确定对坝体非线性响应影响较显著的一些因素。尽量统一可能对坝体非线性响应产生影响的其它时程特性,使得频率非平稳特性成为唯一或少量影响因素之一,从而最大限度地考虑频率非平稳的作用。结果显示,渐进谱峰值结合渐进谱的分布形式可以较好解释大岗山拱坝的非线性计算结果。

Influence of frequency non-stationary earthquakes accelerograms on the nonlinear responses of Dagangshan arch dam

This paper studies the influence of frequency non-stationary input earthquake on nonlinear responses of arc dam through a case study of Dagangshan project.First,the major factors that influence the nonlinear responses of the dam are determined by analyzing the time/frequency-domain features of the input accelerograms selected from various records of actual earthquakes.Then,constraints are implemented on certain factors to eliminate their effects and make the non-stationary frequency a unique factor or a dominant factor on the nonlinear responses.Results show that this is a practical way of maximizing the effect of non-stationary frequency,and that in this way the nonlinear responses of Dagangshan arch dam can be well explained by combining their peak values with their distributed evolutionary spectra.