水石流冲击信号能量分布试验研究  

Energy distribution in spectrum of shock signal for non-viscous debris flow

作　　者：陈洪凯[1,2] 鲜学福[2] 唐红梅[1,2] 张玉萍[1] 何晓英[1] 文光菊[1] 唐兰[1] 

机构地区：[1]重庆交通大学岩土与地质工程系,重庆400074 [2]重庆大学西南资源开发及环境灾害控制工程教育部重点实验室,重庆400044

出　　处：《振动与冲击》2012年第14期56-59,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金(41071017);中国博士后科学基金(200902288;20080430095)

摘　　要：泥石流冲击谱是泥石流固液两相介质运动特性的综合表征,探索泥石流冲击信号的能量大小及其分布特性是合理确定泥石流冲击荷载的关键环节。运用自行研制的试验模型,实施了15种试验工况的泥石流冲击试验,获取了85 000多个测试数据。依据固相比为0.16、粒径组为0.8～1.5 cm水石流冲击测试结果,运用db8小波基变换对试验结果进行8层小波分解,得到频率范围分别为0～0.195Hz,0.195～0.391 Hz,0.391～0.781 Hz,0.781～1.562 5 Hz,1.563～3.125 Hz,3.125～6.25 Hz,6.25～12.5 Hz,12.5～25 Hz和25～50 Hz共九个频率段的冲击信号,据此揭示了不同频段冲击信号能量分布规律。从低频段至中高频段水石流冲击能量非线性衰减,90%以上的冲击能量分布在小于0.195 Hz的低频部分;水石流在中高频段的冲击能量总体呈衰减分布,但在频段三和频段六出现较显著峰值,表明水石流也存在一定阵流现象;水石流中固相粒径越小,低频段至高频段的冲击能量衰减速度越慢。研究成果可为进一步实施泥石流冲击荷载精细实验研究提供一定科学依据。Shock spectrum of debris flow a solid-liquid two-phase medium, is a comprehensive description of its kinetic characteristics. To explore the magnitude and distribution of debris flow impact energy is the key to determine the impact load. Impact tests of debris flow were taken under 15 test conditions, and more than 85000 test data were obtained by using the self-developed test model. Impact signals in nine frequency bands： 0 -0. 195 Hz, 0. 195 -0. 391 Hz, 0. 391 -0.781 Hz, 0.781 -1.5625 Hz, 1.563 -3. 125 Hz, 3. 125 -6.25 Hz, 6.25 -12.5 Hz, 12.5 -25 Hz and25 -50 Hz were obtained during the impact test of water-rock debris flow with solid phase ratio 0.16 and diameter of solid particles 0.8- 1.5cm. The energy distribution in different frequency bands was revealed by the db8 wavelet transform. It is concluded that the impact energy of water-rock debris flow is nonlinearly decreased from low to high frequency bands, more than 90% of the impact energy is distributed in the low frequency band lower than 0. 195Hz, in higher frequency bands, the distribution of impact energy is decayed, while dramatic peak values exist in the third and sixth frequency bands, which means that blast flow exists in water-rock debris flow, and in lower frequency bands, the smaller the grain size of solid phase in water-rock debris flow is, the lower the attenuating rate of impact energy is. The results provide some scientific references to the further study on impact load of debris flow.

关 键 词：水石流 冲击信号 能量分布 离散小波分解方法 冲击试验 

分 类 号：P642.23[天文地球—工程地质学] O359[天文地球—地质矿产勘探]