地震动功率谱改进模型及其在人工地震动合成中的应用  

Improved model of seismic power spectrum and its application in artificial ground motion synthesis

作　　者：丁佳伟 何浩祥[1] 闫晓宇[2] DING Jiawei;HE Haoxiang;YAN Xiaoyu(Beijing Municipal Key Lab of Earthquake Engineering and Structural Retrofit,Beijing University of Technology,Beijing 100124,China;Science and Engineering Teaching Department,The Open University of China,Beijing 100039,China)

机构地区：[1]北京工业大学工程抗震与结构诊治北京市重点实验室,北京100124 [2]国家开放大学理工教学部,北京100039

出　　处：《振动与冲击》2020年第21期258-266,共9页Journal of Vibration and Shock

基　　金：国家重点研发计划(2017YFC1500604);国家自然科学基金项目(51878017)。

摘　　要：地震动具有显著的时频非平稳性和随机性,目前表征地震动时频域特征的强度包络函数和功率谱模型的精准性均需要通过统计分析进行验证。针对时域信号峰值直接对齐等方法无法验证强度包络函数统计特征的局限性,提出基于能量持时的地震动强度统计模型建立方法,验证不同场地类型下的传统强度包络统计模型的准确性。通过统计分析确认基于超越概率随机响应的功率谱模型在高频段存在精度不足,进而提出增加高频抑制项进行修正,结果表明修正公式明显改进了精度。针对传统光滑功率谱模型不能充分表征真实地震动的频域非平稳性,提出光滑噪声功率谱模型,实现地震动功率谱的精细化刻画。提出同时满足反应谱与功率谱精度的时频域双控的人工地震动合成方法,并实现精度较高的地震动生成。Ground motions have significant time-frequency non-stationarity and randomness. The precision of the current intensity envelope function and power spectrum model to characterize ground motions’ time-frequency features should be verified with statistical analysis. Here, to overcome the limitation of the method for direct alignment of peak values of time-domain signals and other ones being not able to verify statistical characteristics of intensity envelope function, a method to establish statistical model of seismic intensity based on energy duration was proposed to verify the accuracy of traditional statistical model of intensity envelope under different site types.Statistical analysis showed that the current power spectrum model based on random response with exceeding probability has insufficient precision in high frequency range.So,a high-frequency suppression term was proposed to be added to the original formula, and do modification.Results showed that the corrected formula can improve the precision obviously. Aiming at the traditional smooth power spectrum model being not able to fully characterize the non-stationarity of actual ground motions in frequency domain, a smooth-noise power spectrum model was proposed to realize fine description of ground motion power spectrum.Finally, an artificial ground motion synthesis method with time-frequency domain dual-control was proposed. It was shown that the proposed method can simultaneously meet the accuracy requirements of response spectrum and power spectrum, and realize higher accuracy ground motion generation.

关 键 词：强度包络函数 能量持时 功率谱 反应谱 地震动合成 

分 类 号：P315.9[天文地球—地震学] TU311.3[天文地球—固体地球物理学]