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泥石流运动要素对声波影响的实验研究
Alternative TitleInfluence of debris flow movement elements on acoustic waves by.experiment
胡雨豪
Subtype硕士
Thesis Advisor马东涛
2018
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Discipline岩土工程
Keyword泥石流 声波 时域 时频域 影响因素
Abstract次声警报是泥石流灾害预警的重要手段之一。目前对泥石流次声的研究多集中于对实测次声特征的统计分析、对算法的拓展,难以实现对泥石流性质和规模的定量警报。分析次声特征与泥石流流量、性质等要素的关系,揭示规模和类型对次声的影响,对推动泥石流次声定量警报,降低漏报、误报率,拓展次声应用前景和减灾防灾具有现实意义。在国家自然科学基金“泥石流次声预警机制及降低误报率的算法研究”(41572347)支持下,进行了不同类型、规模的室内泥石流实验53次,监测到34次有效的泥石流声波信号,利用MATLAB平台,采用HHT变换、快速傅里叶变换和短时傅里叶变换等分析方法对声波数据进行了分析,结合对蒋家沟泥石流声波特征的对比分析,揭示了泥石流运动要素对声波时域和时频域的影响规律。得出如下研究结论:(1)泥石流声波振幅-时间曲线基本呈现增长、稳定和衰减三个阶段,其分别对应于泥石流阵流所产生信号的SON部分、SBO部分和STA部分。(2)无论是稀性、过渡性和粘性泥石流,泥石流声波峰值振幅均随着流量的增加而增高,二者具有明显的线性关系。声波振幅的高低反映泥石流规模的大小,通过采集的声波峰值振幅,采用线性关系式,可以估算泥石流的峰值流量及规模,预测危害大小。(3)泥石流的容重即性质对峰值振幅有着直接影响,随着容重的增加,斜率与截距基本呈现增长趋势,由容重1.3 t?m-3的y = 16.75x + 0.0277演变为2.0 t?m-3的y=50.333x+0.3507;在流量相同的情况下,容重越大,峰值振幅也越大。(4)泥石流声波可划分为5-20Hz低频段(band1),20-35Hz中频段(band2)和35-50Hz高频段(band3)等3个频段。在band1段,容重1.3 t?m-3和1.5 t?m-3的稀性泥石流和容重1.7 t?m-3的过渡性泥石流的振幅增长趋势相同,而容重2.0 t?m-3的粘性泥石流的增长趋势高于前两者;在band2段和band3段,稀性泥石流的振幅增长趋势基本一致,过渡性泥石流和粘性泥石流的增长趋势较大。(5)容重1.3 t?m-3和1.5 t?m-3的稀性泥石流的声波能量均匀分布在三个频段上;容重1.7 t?m-3的过渡性泥石流的声波能量集中在中高两个频段上;容重2.0 t?m-3的粘性泥石流的声波能量集中在中低两个频段上。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识别。 
Other AbstractInfrasound alarm is an important method of early warning of debris flow disaster. At present, the study on the infrasound of debris flow is mainly focused on the statistical analysis of the measured infrasound characteristics and the expansion of the algorithm, and it is difficult to realize the quantitative alarm of the properties and scale of the debris flow. Analysing the relationship between infrasound characteristics and elements such as properties and discharge, revealsing the influence of the size and type on infrasound, would promote the debris flow infrasound quantitative alarm, reduce the rate of false and omission positives, expand the infrasound application prospect and be great significance for disaster prevention and mitigation. With the support of the national natural science foundation “research on the mechanism of debris flow infrasound warning mechanism and the reduction of false alarm rate" (41572347),different types and sizes of indoor debris flow experiments were conducted 53 times, and 34 effective acoustic signals were detected. With MATLAB platform, acoustic wave data are analyzed by the HHT transform and fast Fourier transform and short time Fourier transform. Combined with comparative analysis of the Jiangjia gully acoustic characteristics, the influence law of the debris flow movement elements on acoustic time domain and frequency domain was revealsed. The following conclusions are drawn:(1) The acoustic amplitude-time curve of debris flow basically shows growth, stability and attenuation, which correspond to the SON part, SBO part and STA part of the signal generated by the surge of debris flow.(2) The peak amplitude of debris flow is increased with the increase of flow rate in both the dilute, transitional and viscous debris flow, and the two have obvious linear relationship. The acoustic amplitude can reflect the size of the debris flow. through the acquisition of acoustic peak amplitude and the linear relation, the peak discharge and scale of debris flow can be estimated and damage size can be predicted.(3) Density of debris flow (properties) have a direct impact on the peak amplitude, namely with the increase of density, slope and intercept of basic present growth trend, y = 16.75 x + 0.0277 of 1.3 t·m-3 evolved into y=50.333x+0.3507 of 2.0 t·m-3; In the case of the same discharge, the larger the density, the larger the peak amplitude.(4) The acoustic wave can be divided into 5-20hz low frequency band (band1), 20-35hz middle frequency band (band2) and 35-50hz high band (band3). In band1, for the dilute debris flow of 1.3 t·m-3 and 1.5 t·m-3 and the transitional debris flow of 1.7 t·m-3, the amplitude growth trend is the same, and the viscous debris flow of 2.0 t·m-3 is higher than the former two;In band2 and band3, the amplitude growth trend of dilute debris flow is basically consistent, and the growth trend of transitional and viscous debris flows is larger.(5) The acoustic energy of the dilute debris flow of 1.3 t·m-3 and 1.5 t·m-3 is evenly distributed in three frequency bands;The acoustic energy of the transitional debris flow of 1.7 t·m-3 is concentrated in the middle and high frequency bands;The acoustic energy of the viscous debris flow of 2.0 t·m-3 is concentrated in the middle and low frequencies.By analyzing the distribution of acoustic energy, the nature and type of debris flow can be identified. 
Pages113
Language中文
Document Type学位论文
Identifierhttp://ir.imde.ac.cn/handle/131551/24764
Collection山地灾害与地表过程重点实验室
Affiliation中国科学院成都山地灾害与环境研究所
First Author Affilication中国科学院水利部成都山地灾害与环境研究所
Recommended Citation
GB/T 7714
胡雨豪. 泥石流运动要素对声波影响的实验研究[D]. 北京. 中国科学院大学,2018.
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