【摘要】 以上海某深覆盖场地为背景,分别选用普通El-Centro波和长周期HKD123波作为输入,采用正交化HHT方法探讨地震动非平稳性对深覆盖场地地震反应的影响。首先,采用正交化HHT方法分析El-Centro波和HKD123波的局部功率谱,比较这两条波的能量分布情况。然后,采用等效线性波动法求取深覆盖场地的地表反应,并采用正交化HHT法对其进行时频特性分析,比较不同强度的不同类型地震波作用下深覆盖场地的反应差异,以及能量分布的变化情况。结果表明,地震动的非平稳性对深覆盖场地非线性地震反应的影响不容忽视。更多还原

【Abstract】 Based on the Shanghai soil layer with deep deposit,this paper investigates the effect of ground motion non-stationarity on the seismic response of soil layer with deep deposit by the orthogonal HHT method.Firstly,the energy distribution of the normal El-Centro wave and long-period HKD123 wave were researched by the orthogonal HHT method,and then,the ground responses of soil layer with deep deposit under these waves input with different amplitude were calculated by the equivalent linear fluctuation method.These ground responses and their energy distribution were also compared and analyzed based on the time-frequency method.The results indicated that the effect of ground motion non-stationarity is indispensable when taking the nonlinear seismic response to soil layer with deep deposit.更多还原