SPECTRUM CHARACTERISTICS OF STRATIFIED ROCK SLOPES USING SHAKING TABLE TEST

By means of large-scale shaking table test, this paper analyzes the dynamic response of stratified hard rock and soft rock slopes with anti-dipping strata or dipping strata subject to strong earthquakes. The results show that: the seismic signal of the slope shoulder contains the characteristic of the slope structure and material. The processed signal using Fast Fourier Transform Algorithm contains some feature of the slope itself. This method is practical in the shaking table test. The FFT spectrum of discrete frequency signal shows that the derivative frequency of the anti-dip slope is higher than that of the dip slope under the vertical seismic force. And as horizontal seismic force is applied, the hard rock dip slope and the soft rock anti-dip slope have higher magnitude and their predominant frequency is more concentrated than those the hard rock anti-dip and soft rock dip slope. The seismic response of the hard rock dip slope is more significant than that of the soft rock dip slope. As a natural earthquake record is applied to the model vertically, the FFT spectrum of the dip slope has the same pattern as the shaking table, and the anti-dip slope has more magnification in certain frequency. While a horizontal natural record is applied, the four models show more consistency, which means at this condition, the influence of structure and the lithology are non-significant.