层状场地地震反应放大谱分析

The amplified spectra of seismic response on layered site

放大谱能够准确地反映出场地土体的固有周期和放大率等特性,本文针对工程中常见的层状场地,采用线性和非线性分析方法计算了层状场地中地表相对于基岩的放大谱,分析了两种情况下放大谱的特性及不同点,分析了输入地震动峰值和频谱对放大谱的影响.研究表明:在线性情况下,输入地震动频谱和幅值对放大谱没有影响;在非线性情况下,输入地震动幅值对放大谱影响较大,输入地震动频谱对放大谱虽有影响,但影响不大.

Amplified spectra could reflect the natural periods of site and the magnification on ground motion. In the paper, the amplified spectra of seismic response on layered site were calculated with the method of linear and nonlinear. The characteristics and differences of the amplified spectra about the linear and nonlinear methods, and the influence of input ground motion on amplified spectra were also analyzed. The results indicate that the amplitude and spectrum of ground motion have no effect on the amplification spectra in the linear case, while in the nonlinear case, the amplitude of input ground motion has a greater impact on the amplification spectra and the spectrum of ground motion has little effect on the amplified spectra.