基于地震波解译的 2000 年易贡滑坡 － 碎屑流动力学过程分析

为更好地研究 2000 年易贡滑坡碎屑流动力学过程，开展该次滑坡碎屑流地震波解译工作，以该次滑坡碎屑流的地震波和遥感影像为基础，通过快速傅里叶变化和人工识别等手段，解译得出该次滑坡碎屑流地震波信号参数、动力学过程及其特征参数。研究结果表明: (1)该滑坡 － 碎屑流的傅里叶主频率和主功率为 2. 0 Hz，最大峰值加速度为 0. 45g，最大地震动速度为 0. 786 m /s，最大地震动振幅 64 cm。(2)该滑坡 － 碎屑流的动力学过程分为崩滑区裂隙贯通崩滑过程，滑坡转化为碎屑流过程和碎屑流运动堆积过程。崩滑区裂隙贯通崩滑过程中地震波振幅逐渐增大，频率逐渐升高。受强降雨和沟道源头圈闭地形的影响，滑坡转化为碎屑流过程中振幅达到最高值，频率有所减小。受沟道弯曲程度的影响，碎屑流运动堆积过程中振幅呈现波状变化趋势，频率呈逐渐减小的趋势。(3)该滑坡碎屑流的流速过程呈现出一个总体上凸、但存在激烈振动的过程。滑坡 － 碎屑流平均速度为 30. 12m /s，滑坡 － 碎屑流在起点 O － A 段的平均速度为 89. 89 m /s，在 A － B 段平均速度最大，为 120. 98m /s，在出山口 E 点的平均速度为 48. 7 m /s。研究成果为进一步研究巨型滑坡 － 碎屑流动力学过程和运动机理提供参考。

Analysis on debris flow dynamic process of 2000 Yigong Landslide interpreted based onseismic wave

In order to further study the debris flow dynamic process of the 2000 Yigong Landslide，the seismic wave interpretation of debris flow induced by the landslide is carried out，for which the seismic wave signal parameters，dynamic process and characteristics of the debris flow are interpreted and obtained by means of the fast Fourier transform，manual identification，etc. based on the seismic wave data and remote sensing image of the landslide-debris flow. The study result shows that (1) The main frequency and main power of Fourier of the landslid-debris flow are 2. 0 Hz with the maximum peak acceleration of 0. 45 g，the maximum seismic dynamic velocity of 0. 786 m/s and the maximum seismic dynamic amplitude of 64 cm. (2)The dynamic process of the landslide-debris flow can be divided into the fissure perforating and sliding process of the slump zone，the transformation process from landslide to debris flow and the accumulation process ofdebris flow movement. The seismic wave amplitude gradually increases during the fissure perforating and sliding process of the slump zone along with the gradual increase of the frequency. Under the effects from the strong rainfall and trapping topography of the gully head，the amplitude during the transformation process from landslide to debris flow reaches to its highest value along with the decrease of the frequency to some extent. Under the effect from the gully bending degree therein，the amplitude during the accumulation process ofdebris flow movement shows a fluctuated change process along with a trend of gradual decrease of the frequency. (3)The flow velocity process of the landslidedebris flow is generally protruded，but an intensive vibration process is there. The mean velocity of the landslide-debris flow is 30. 12 m/s，in which it is 89. 89 m/s at the starting point—O － A section，is the maximum of 120. 98 m/s at A － B section and is 48. 7 m/s at the point E of the mountain-pass therein. The study result provides more time and intensity records for the further study on the dynamic process and movement mechanism of huge landslide-debris flow.