摘要
泥石流的声波是泥石流声波预警的重要媒介,声波的特性从一定程度上可以反映泥石流的性质和规模。通过开展容重为1. 3 t·m^(-3)、1. 5 t·m^(-3)、1. 7 t·m^(-3)、2. 0 t·m^(-3)和不同流量(规模)的34次室内泥石流实验,采集了泥石流流速、流量(规模)数据及声波信号,采用短时傅里叶变换(STFT)和滤波器对声波信号进行处理,分析研究了泥石流容重、流量对声波最大振幅、时域频域、声波能量的影响规律。实验表明:声波振幅的高低可反映泥石流规模的大小,泥石流声波最大振幅与流量表现出线性正相关性;泥石流声波最大振幅随容重呈线性增长趋势,拟合函数系数与容重满足线性正相关性,据此可以估算泥石流的峰值流量及规模;不同容重的泥石流声波能量分布频带不同,稀性泥石流的声波能量均匀分布在高(Band3)、中(Band2)、低(Band1)三个频带上,过渡性泥石流的声波能量集中在中、高两个频带上,粘性泥石流的声波能量集中在中、低两个频带上。通过对声波能量分布的分析,可以对泥石流的性质和类型进行判别。
The acoustic wave of debris flow serves as an important indicator for debris flow early warning,because it conveys reliable information of the property and the scale of a moving debris flow.In this study,34 debris flow experiments were designed with combination of the varied density of 1.3 t·m^-3,1.5 t·m^-3,1.7 t·m^-3,2.0 t·m^-3 and different volume discharge(scale)to collect the data of velocity,discharge(scale)and acoustic signal for analysis.It used the short-time Fourier transform(STFT)and filters to process acoustic signals and the quantitative relationship between peak amplitude and discharge,the distribution of acoustic energy were studied.Results showed that the peak amplitude of debris flow acoustic wave had a linearly positive correlation with its discharge.Peak amplitude increased linearly with the density,and fitting coefficient was linearly and positively correlated to density.The acoustic energy of debris flow varied with different bulk density.The acoustic energy of dilute debris flow was distributed evenly in three frequency bands:high frequency band(Band 3),middle frequency band(Band 2)and low frequency band(Band 1).The transitional debris flow behaved mainly in the middle and high frequency bands,whereas viscous debris flow presented in the middle and low frequency bands.The comprehensive understandings of debris flow acoustic characteristics by experiments would provide an insight into the early warning of debris flow for its type,scale and energy potential.
作者
袁路
胡雨豪
马东涛
李梅
YUAN Lu;HU Yuhao;MA Dongtao;LI Mei(Institution of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Mountain Hazards and Earth Surface process,Chinese Academy of Sciences,Chengdu 610041,China;CCTEG Chongqing Engineering Co.Ltd,Chongqing 400016,China;China University Of Geosciences,Beijing 100083,China)
出处
《山地学报》
CSCD
北大核心
2018年第6期889-897,共9页
Mountain Research
基金
国家自然科学基金项目(41572347).
关键词
泥石流
性质
规模
声波
振幅
频率
debris flow
property
discharge
acoustic wave
amplitude
frequencies
