基于推覆分析的输入地震动加速度记录核定准则

Push-over-based criteria for identifying input seismic accelerogram

反应谱理论的数学模型是平稳高斯随机过程,反应谱法确定的线性地震反应具有统计意义上平均的数学意义。推广到非线性分析,推覆分析得到的目标位移及层位移曲线等物理量同样具有统计意义上平均地震反应的数学意义。由于地面运动的不可预测性及其动力非线性分析结果的离散性,对于标准设防类和重点设防类建筑物,笔者认为核定1,2条使结构非线性行为能满足统计平均意义的地震动记录作为输入地震动是可以接受的。按此设防原理,提出应用推覆分析的层位移或层间位移曲线作为准则来核定输入地震动加速度记录的理论,并成功地应用于超限高层建筑的抗震性能评估中。

The spectral theory is based on Gauss stationary random process, and the linear seismic responses obtained by the spectral method are statistical mean values. As an extension to non-linear analysis, it is consensus that the physical measures such as target displacement and story drift patterns along the height of a building determined by the Push-over analysis are also the mean of the seismic responses in the statistical meaning. Owing to un-prediction of the ground motion for specific site and dispersion of the results by dynamic non-linear analysis, it may be reasonable that identification of one or two accelerograms of ground motion from the carefully selected set of seismic records as the system input, which will enable the non-linear behaviour of the structure to meet the requirement of statistical mean value. Following such design philosophy, authors present the Push-over-based identifying seismic wave theory, upon which the input seismic waves for dynamic non-linear analysis of seismic categories B or C buildings are identified by using the displacement or story drift pattern obtained by Push-over analysis. As an example, the seismic performance of an irregular tall building was successfully estimated by using the identification criteria presented here.