摘要
泥石流的能量转化主要集中于运动过程中,泥石流冲击压力随时间变化的过程是其能量不断变化的综合表现。本文分析了泥石流能量转化过程及冲击荷载的紊流形态,并根据其脉动特性,将泥石流冲击荷载作为信号进行研究。以大型泥石流模型试验为基础,利用小波时频分析方法将试验测取的泥石流冲击荷载映射为时间与频率的联合信号,得到同一时间9个频段内的能量强度。从冲击荷载的能量分布可以看出,稀性泥石流95%以上的波动能集中在低频段内(0～6.25Hz),从而为深入研究泥石流冲击机制及防治结构动态荷载设计提供了一些理论依据。
The energy transformation of debris flow mostly concentrates on its movement process.Moreover the variation process of impact signals of debris flow along with time is a general phenomenon.The paper analyzes the energy translation process of debris flow and the turbulence characteristics of impact loads.Based on the fluctuation characteristics,the impact loads of debris flow are regarded as signals to study.Using the wavelet time-frequency analysis,the impact loads of debris flow in testing results are mapped into the associated signals between time and frequency and obtain signal particulars of 9 different frequency bands.According to the results of energy distribution,more than 95%fluctuation energy is concentrated on low frequency band（0～6.25 Hz）.So it can offer some basis for lucubrating impact mechanism of debris flow and optimize the load design of controlled structures.
出处
《防灾减灾工程学报》
CSCD
2011年第3期255-260,共6页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(41071017)
重庆市重点自然科学基金项目(2008BA0015)
中国博士后科学基金项目(20080430095)
中国博士后科学基金特别资助项目(200902288)
高校博士点基金项目(20060618001)资助
关键词
泥石流
冲击荷载
小波
时频分析
能量分布
debris flow
impact loads
wavelet
time-frequency analysis
energy distribution
