对已有强震地面运动功率谱模型的改进

Some Improvements on Exiting Power Spectral Models of Strong Earthquake Ground Motion

为使得地震动功率谱模型在低频区域更好的模拟实际地震动的能量分布,同时兼顾模型的简单性和实用性,在已有地震动功率谱模型基础上提出了修正金井清模型和修正胡聿贤-周锡元模型.文中推导了具有这2种功率谱特征的平稳过程作用下单自由度结构的随机响应计算公式;基于单自由度结构随机反应对6种功率谱模型进行了对比.结果表明:修正胡聿贤-周锡元模型构造简单,能合理描述强震地面运动过程的频域能量分布,其对应平稳随机过程作用下结构随机响应也与加速度时程样本对应的结果相符,适于工程应用;修正金井清模型在一定程度上修正了金井清模型的缺陷,可以替代金井清模型.

in order to simulate the energy distribution in low frequency region of the earthquake ground motion better by the models of power spectral density,and taking into account the simplicity and usability at the same time,two types of modified power spectral density（PSD） models are presented in this study： modified Kanai-Tajimi model and modified Hu-Zhou model.The stochastic response of the single degree of freedom structure disturbed by the stationary stochastic process with the frequency characters represented by above two PSD models are deducted;According to the stochastic response of single degree-of-freedom structure subjected to stationary random processes,six kinds of PSD models have been compared. The investigations shows that the modified Hu-Zhou model can reasonably represent the energy distribution of seismic ground motion in frequency domain,the earthquake response of structure excited by modified Hu-Zhou model consistent with the typical real acceleration records.The modified Kanai-Tajimi model make up the low-frequency-default of kanai-Tajimi model to some extent,and then can be used as its replacement.