李果, 华宏亮, 赵建军. 2016: 层状斜坡振动台实验的频谱特性研究. 工程地质学报, 24(5): 959-966. DOI: 10.13544/j.cnki.jeg.2016.05.027
    引用本文: 李果, 华宏亮, 赵建军. 2016: 层状斜坡振动台实验的频谱特性研究. 工程地质学报, 24(5): 959-966. DOI: 10.13544/j.cnki.jeg.2016.05.027
    LI Guo, HUA Hongliang, ZHAO Jianjun. 2016: SPECTRUM CHARACTERISTICS OF STRATIFIED ROCK SLOPES USING SHAKING TABLE TEST. JOURNAL OF ENGINEERING GEOLOGY, 24(5): 959-966. DOI: 10.13544/j.cnki.jeg.2016.05.027
    Citation: LI Guo, HUA Hongliang, ZHAO Jianjun. 2016: SPECTRUM CHARACTERISTICS OF STRATIFIED ROCK SLOPES USING SHAKING TABLE TEST. JOURNAL OF ENGINEERING GEOLOGY, 24(5): 959-966. DOI: 10.13544/j.cnki.jeg.2016.05.027

    层状斜坡振动台实验的频谱特性研究

    SPECTRUM CHARACTERISTICS OF STRATIFIED ROCK SLOPES USING SHAKING TABLE TEST

    • 摘要: 本文通过大型振动台试验,对硬岩顺层、反倾和软岩顺层、反倾4类结构岩体边坡的地震动力响应的频谱特性进行了分析。实验结果表明:传递至坡肩的振动信号,是一个包含了斜坡本身材料和结构特征的复杂信号集合。对这一信号的傅里叶频谱进行分析获得的特征信息,与斜坡本身的结构特性吻合,说明在振动台试验中采用这一方法对斜坡结构进行研究是可行的。在本次试验中,当不同频率的垂直向震动施加于边坡时,坡肩衍生振动频率的幅值呈现了明显的反倾高于顺层,硬岩高于软岩的特性;而水平震动施加于边坡时,则硬岩顺层,软岩反倾斜坡具有更高的幅值,频率也更集中于特定的卓越频段,而硬岩反倾和软岩顺层斜坡的水平震动响应则相对不显著。另外,硬岩顺层斜坡对震动的响应表现比软岩顺层明显,而软岩反倾的反应比硬岩反倾明显。当施加垂直向天然波信号时,顺层斜坡的傅里叶频谱图像与台面波形基本保持一致,而反倾斜坡表现为对特定频率段的幅值放大更加显著。水平向加载天然波信号时各个斜坡呈现了更多的一致性,表明此工况下坡体结构与岩性的影响则明显较不显著。

       

      Abstract: 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.

       

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