碎屑流-堵河震动频谱特征识别的试验研究  

Experiment on the Identification of Seismic Spectrum Characteristics of Granular Flow Blocking Rivers

作　　者：杨宗佶[1] 刘刚 刘世皓 付校龙 董悟凡 YANG Zongji;LIU Gang;LIU Shihao;FU Xiaolong;DONG Wufan(Chengdu Institute of Mountain Hazards and Environment,Chinese Academy of Science,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院大学,北京100049

出　　处：《灾害学》2021年第4期19-26,共8页Journal of Catastrophology

基　　金：国家自然科学基金项目(41771021);中科院STS区域重点项目(KFJ-STS-QYZD-172)。

摘　　要：主动监测碎屑流运动过程中产生的地震动信号可用于灾害运动演进过程评估、监测预警。通过开展室内模型试验,模拟了不同坡度下,山前平地型碎屑流和堵河型碎屑流运动过程,并采用经验模式分解(EMD)和短时傅里叶变换(STFT)相结合的时频分析法分析了其震动特征。结果表明:①根据震动信号将碎屑流运动过程分为分离启动阶段、加速阶段、冲击接触阶段、堆积阶段,并分析了各阶段的时域、时频域和瞬时能量特征;②碎屑流相对运动产生的地震信号的能量强度、频率和振幅与碎屑流相对于滑槽的运动状态相关性强;③斜坡坡度增大时,对波形曲线特征、能量分布特征影响显著,同时加速阶段和冲击接触阶段的最大振幅逐渐增加,呈现较好的线性关系;④山前平地型碎屑流和堵河型碎屑流在堆积阶段的地震波波形、时频图和瞬时能量变化都具有明显差别,并且前者在堆积阶段的最大振幅在相同斜坡坡度下都大于后者,以上指标可作为碎屑流-堵河的超前识别依据。In-situ monitoring the ground seismic signals generated during the movement of the granular flow can be used for the evaluation of the flow dynamic evolution and early warning.Laboratory experiments are carried out to study the movement process of the piedmont flat-type granular flow and simulated subsequent the river-blocking under different gradient,and the time-frequency analysis method that combination EMD and STFT is used to analysis its spectrum characteristics.Experimental results shown that:(1)According to the seismic signal,the dynamic process of simulated granular flow is divided into the separation start phase,the acceleration phase,the impact contact phase,and the accumulation phase,additionally,the time domain,time-frequency domain and instantaneous energy characteristics of each phase are analyzed;(2)The energy intensity,frequency and amplitude of the seismic signal generated by the relative movement of the granular flow have a strong correlation with the movement state of the granular flow relative to the chute;(3)the gradient of slope remarkably affect the characteristics of the wave curve and the energy distribution.Significantly,the maximum amplitudes of the acceleration phase and the impact contact phase gradually shows a good linear relationship;(4)The piedmont flat-type granular flow and the river-blocking granular flow caused the waveform,time-frequency diagram,instantaneous energy changes as well as the maximum amplitude of the piedmont flat-land granular flow in the accumulation stage is distinguish with the river-blocking granular flow,which could be quantified as discriminate signals for identification of river-blocking granular flow.

关 键 词：模型实验 碎屑流 坡度 震动信号 频谱特征 

分 类 号：P642.23[天文地球—工程地质学] X43[天文地球—地质矿产勘探]