Abstract：
The earthquake wave is very complex containing time, frequency and amplitude characteristics, in the process of calculating the dynamic response of layered site, ignoring any characteristic of earthquake wave can lead a large mistake in the calculation result. Based on some assumption, a mathematic mode is established in this paper, and the orthogonal theory of vibration mode and the Hilbert-Huang Transfer are used to establish the time-frequency analysis method, which takes all the time, frequency and amplitude characteristics into account. The research result of this paper provides a simple and scientific method for dynamic response assessment of layered site.
