不同含水率离子型稀土矿剪切破坏微震信号特征研究

Investigation on Microseismic Signal Features of Ionic Rare Earth Ore with Different Water Content

微震监测被认为是离子型稀土矿边坡破坏过程的有效监测方法,基于微震信号区分稀土矿的剪切破坏过程是实现边坡失稳精准预警的前提。以江西赣州定南县某稀土矿山1~2 m深矿土为实验土样,利用微震监测技术在室内开展不同含水率条件下力−微震监测剪切模拟实验,研究了不同含水率下离子型稀土矿发生剪切破坏时的微震信号特征。结果表明:微震信号的产生与应力升降有较好的相关性;随着含水率增加,微震信号释放模式表现为由主震型向群震型特征过渡,微震信号释放的总能量增加,出现多次振幅峰值,稀土矿微震能量释放更加活跃;微震信号的主频率范围在3.72~5.46 Hz,随着含水率的增加而增加;频谱质心在6 Hz左右波动,平均振幅随着含水率的增加而增大。研究结果可为微震信号判别离子型稀土矿滑坡破坏的发生提供参考。

Microseismic monitoring is considered an effective method for monitoring the slope failure process of ionic rare earth mines.Distinguishing the shear failure process of rare earth ore based on microseismic signals is a prerequisite for achieving precise early warning of slope instability.The samples buried 1 to 2 meters were collected for experimental testing in a rare earth mine in Dingnan County,Jiangxi Province,microseismic monitoring technology was employed to conduct force−microseismic monitoring shear simulation tests under different moisture content conditions.The study investigated the microseismic signal characteristics during the shear failure of ionic rare earth ore at various moisture contents.The results showed that the generation of microseismic signals was well correlated with the rise and fall of stress.As the moisture content increased,the shear box's peak shear strength increased due to the influence of unit weight.The release pattern of microseismic signals transitioned from a mainshock type to a swarm−like characteristic,with an increase in the total energy released by the microseismic signals,multiple amplitude peaks appeared,and the release of microseismic energy in rare earth mines became more active.The dominant frequency range of the microseismic signals was between 3.72 Hz and 5.46 Hz,increasing with the increase in moisture content.The spectral centroid fluctuated around 6 Hz,and the average amplitude increased with the increase in moisture content.The research results can provide a reference for the identification of ion−type rare earth mine landslide failures based on microseismic signals.