超随机特性对地震动谱特性和时间历程的影响

本文从单个地震动样本的角度分析了超随机部分对地震动波形的影响，认为自相关函数噪声部分或功率谱的随机波动部分对地震动波形的影响不大，对地震动的波形起主要控制作用的是地震动的相位谱或相位差谱，而自相关函数的噪声部分（或功率谱的随机波动成分）只对地震动波形起一定程度的调整作用。文中基于平稳随机过程的理论，用蒙特卡罗方法分析了自相关函数噪声项对人工合成地震动振幅和反应谱的影响：由于自相关函数的随机噪声项对地震动总功率或平方和的贡献为零，因此随机噪声项对合成地震动幅值的影响不大，但是由于自相关函数随机噪声项明显改变了地震动功率谱的形状和分布特征，使其出现了明显的波动，也在一定程度上提高了平均反应谱的峰值，从而对平均反应谱也产生一些影响。考虑地震动自相关函数中的随机噪声部分有助于更真实地模拟和反映地震动的真实特性。

The effect of the super-randomness on spectral property and time history of strong ground motion

From the view of the sample analysis, this paper indicates that the effect of the super-random part in the autocorrelation function or in the power spectra on the wave-shape of ground motion is not considerable, and the phase spectra or the phase-difference spectra are the main controlling factor of the wave-shape of ground motion. The super-random part would modify the wave-shape of ground motion locally. Based on the stationary random process, the Monte Carlo method was used to analyze the effect of the random noise part in auto-correlation on the peak value of man-made seismic wave and on the response spectra as well. Due to the zero contribution of the noise part of auto-correlation to the total power of seismic wave, the effect of the noise part on the man-made seismic wave amplitude is insignificant. But because the noise part greatly changes the frequent-domain distribution of the power spectrum, the random part in autocorrelation function leads to some effects on the response spectra. However, considering the super-randomness will be in favor of simulating the real features of ground motion.