泥石流浆体与固体颗粒冲击信号能量分布研究

用小波分析方法对5种浆体黏度、5种固相比与4种颗粒粒径组合的85组泥石流冲击室内模型实验所得冲击信号进行消噪、时频处理,通过对降噪的泥石流冲击信号进行冲击能量计算并分析实验中泥石流冲击能量与频谱间关系。结果表明,随浆体黏度、固相比及颗粒粒径增大,泥石流冲击信号能量呈增长趋势,且相同浆体黏度下固体颗粒粒径大于1.3~1.5 cm时,泥石流冲击能量增幅明显。将冲击信号分解为9个频段(0~1.958 Hz、1.958~3.906 Hz、3.906~7.812 Hz、7.812~15.625 Hz、15.625~31.25 Hz、31.25~62.5 Hz、62.5~125 Hz、125~250 Hz、250~500 Hz),泥石流冲击信号96%以上能量聚集在频率0~1.958 Hz的低频段a8内。该结果对推动泥石流动力特性研究具有积极意义。

Experimental study on the energy distribution characteristics of debris flow impacting signals considering the slurry viscosity and particle

 A physical experimental model in laboratory was established for debris flow, and 85 groups’ conditions were done considering the compounding of five slurry viscosities, five solid phase ratios and four grain diameters. The impacting force of debris flow under the experimental conditions were denoised and time-frequency disposed by wavelet method, then the impacting signals were broken down to nine frequency range (0~1.958 Hz, 1.958~3.906 Hz, 3.906~7.812 Hz, 7.812~15.625 Hz, 15.625~31.25 Hz, 31.25~62.5 Hz, 62.5~125 Hz, 125~250 Hz, 250~500 Hz) and the energy distribution characteristics of each frequency range were calculated. The results show that, firstly, general impacting energy increases with the increase of slurry viscosity, solid phase ratio and grain diameter. Secondly, energy distributing law of debris flow in approximate parameter (a8) frequency range is the same with general energy distribution, and more than 96 percentages of the energy colleted at 0~1.958Hz frequency range. The result is positive in the studies on dynamical features of debris flow.