空间相关非平稳地震动反应谱拟合

为了给大跨度结构的抗震分析提供空间多点相关地震动加速度时程,在前人研究的基础上,提出根据标准设计反应谱合成非平稳空间相关多点地震波的方法.从规范反应谱出发得到功率谱,然后由地震动的空间相关性得到功率谱矩阵,用三角级数法生成各点地震动.生成的地震波具有地震动的空间相关性,同时还考虑了强度和频率的双重非平稳性, 在保证相关性的前提下对初始波进行修正使其反应谱与规范反应谱逼近.数值算例表明,利用该方法生成的地震动加速度反应谱具有较高的拟合精度,合成的多点时程可用于大坝等延伸结构多点激励的地震动输入.

Fitting of response spectra for spatially correlated non-stationary ground motion

In order to provide spatially correlated multi-station ground motion for the seismic analysis of structures with large spans, a method for the generation of spatially correlated non-stationary multi-station ground motion compatible with the code response spectra is proposed based on previous research. The power spectra were determined using the code response spectra. The matrix of the power spectra was then obtained from the spatial correlation of the ground motion, and the ground motion at various stations was generated using the trigonometric series method. The generated seismic waves were spatially correlated to the ground motion, and considered the double non-stationary properties of strength and frequency. Under the prequisite of ensuring correlation, the original waves were modified, and their response spectra were made to be closer to the code response spectra. Numerical simulations show that the response spectra of the ground motion generated by the proposed method are of high precision, and the generated multi-station hydrographs of ground motion can be used as the input of ground motion for the analysis of structures such as dams considering the effect of multi-station excitation.